diff --git a/README.md b/README.md
index 52a2ee79d4..2b2a74ef7d 100644
--- a/README.md
+++ b/README.md
@@ -1440,6 +1440,25 @@ line-length = 120
 
 ---
 
+#### [`format`](#format)
+
+The style in which violation messages should be formatted: `"text"` (default), `"grouped"`
+(group messages by file), or `"json"` (machine-readable).
+
+**Default value**: `"text"`
+
+**Type**: `SerializationFormat`
+
+**Example usage**:
+
+```toml
+[tool.ruff]
+# Group violations by containing file.
+format = "grouped"
+```
+
+---
+
 #### [`per_file_ignores`](#per_file_ignores)
 
 A list of mappings from file pattern to check code prefixes to exclude, when considering any
diff --git a/flake8_to_ruff/src/converter.rs b/flake8_to_ruff/src/converter.rs
index b8099817a3..9a0ab39594 100644
--- a/flake8_to_ruff/src/converter.rs
+++ b/flake8_to_ruff/src/converter.rs
@@ -251,6 +251,7 @@ mod tests {
             external: None,
             fix: None,
             fixable: None,
+            format: None,
             ignore: Some(vec![]),
             line_length: None,
             per_file_ignores: None,
@@ -291,6 +292,7 @@ mod tests {
             external: None,
             fix: None,
             fixable: None,
+            format: None,
             ignore: Some(vec![]),
             line_length: Some(100),
             per_file_ignores: None,
@@ -331,6 +333,7 @@ mod tests {
             external: None,
             fix: None,
             fixable: None,
+            format: None,
             ignore: Some(vec![]),
             line_length: Some(100),
             per_file_ignores: None,
@@ -371,6 +374,7 @@ mod tests {
             external: None,
             fix: None,
             fixable: None,
+            format: None,
             ignore: Some(vec![]),
             line_length: None,
             per_file_ignores: None,
@@ -411,6 +415,7 @@ mod tests {
             external: None,
             fix: None,
             fixable: None,
+            format: None,
             ignore: Some(vec![]),
             line_length: None,
             per_file_ignores: None,
@@ -459,6 +464,7 @@ mod tests {
             external: None,
             fix: None,
             fixable: None,
+            format: None,
             ignore: Some(vec![]),
             line_length: None,
             per_file_ignores: None,
@@ -534,6 +540,7 @@ mod tests {
             external: None,
             fix: None,
             fixable: None,
+            format: None,
             ignore: Some(vec![]),
             line_length: None,
             per_file_ignores: None,
diff --git a/src/cli.rs b/src/cli.rs
index 0314203cfa..b2a2cd4199 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -7,8 +7,9 @@ use rustc_hash::FxHashMap;
 use crate::checks::CheckCode;
 use crate::checks_gen::CheckCodePrefix;
 use crate::logging::LogLevel;
-use crate::printer::SerializationFormat;
-use crate::settings::types::{FilePattern, PatternPrefixPair, PerFileIgnore, PythonVersion};
+use crate::settings::types::{
+    FilePattern, PatternPrefixPair, PerFileIgnore, PythonVersion, SerializationFormat,
+};
 
 #[derive(Debug, Parser)]
 #[command(author, about = "Ruff: An extremely fast Python linter.")]
@@ -77,8 +78,8 @@ pub struct Cli {
     #[arg(long, value_delimiter = ',')]
     pub per_file_ignores: Vec<PatternPrefixPair>,
     /// Output serialization format for error messages.
-    #[arg(long, value_enum, default_value_t = SerializationFormat::Text)]
-    pub format: SerializationFormat,
+    #[arg(long, value_enum)]
+    pub format: Option<SerializationFormat>,
     /// Show violations with source code.
     #[arg(long)]
     pub show_source: bool,
@@ -143,8 +144,6 @@ pub fn extract_log_level(cli: &Cli) -> LogLevel {
         LogLevel::Quiet
     } else if cli.verbose {
         LogLevel::Verbose
-    } else if matches!(cli.format, SerializationFormat::Json) {
-        LogLevel::Quiet
     } else {
         LogLevel::Default
     }
diff --git a/src/commands.rs b/src/commands.rs
index 3b37012bec..e8aea7ffd1 100644
--- a/src/commands.rs
+++ b/src/commands.rs
@@ -6,7 +6,7 @@ use walkdir::DirEntry;
 
 use crate::checks::CheckCode;
 use crate::fs::iter_python_files;
-use crate::printer::SerializationFormat;
+use crate::settings::types::SerializationFormat;
 use crate::{Configuration, Settings};
 
 /// Print the user-facing configuration settings.
diff --git a/src/main.rs b/src/main.rs
index a6c932919c..e14dc8b5e1 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -23,8 +23,9 @@ use ::ruff::fs::iter_python_files;
 use ::ruff::linter::{add_noqa_to_path, autoformat_path, lint_path, lint_stdin, Diagnostics};
 use ::ruff::logging::{set_up_logging, LogLevel};
 use ::ruff::message::Message;
-use ::ruff::printer::{Printer, SerializationFormat};
+use ::ruff::printer::Printer;
 use ::ruff::settings::configuration::Configuration;
+use ::ruff::settings::types::SerializationFormat;
 use ::ruff::settings::{pyproject, Settings};
 #[cfg(feature = "update-informer")]
 use ::ruff::updates;
@@ -189,14 +190,7 @@ fn inner_main() -> Result<ExitCode> {
     // Extract command-line arguments.
     let cli = Cli::parse();
     let fix = cli.fix();
-
     let log_level = extract_log_level(&cli);
-    set_up_logging(&log_level)?;
-
-    if let Some(code) = cli.explain {
-        commands::explain(&code, cli.format)?;
-        return Ok(ExitCode::SUCCESS);
-    }
 
     if let Some(shell) = cli.generate_shell_completion {
         shell.generate(&mut Cli::command(), &mut std::io::stdout());
@@ -205,17 +199,9 @@ fn inner_main() -> Result<ExitCode> {
 
     // Find the project root and pyproject.toml.
     let project_root = pyproject::find_project_root(&cli.files);
-    match &project_root {
-        Some(path) => debug!("Found project root at: {:?}", path),
-        None => debug!("Unable to identify project root; assuming current directory..."),
-    };
     let pyproject = cli
         .config
         .or_else(|| pyproject::find_pyproject_toml(project_root.as_ref()));
-    match &pyproject {
-        Some(path) => debug!("Found pyproject.toml at: {:?}", path),
-        None => debug!("Unable to find pyproject.toml; using default settings..."),
-    };
 
     // Reconcile configuration from pyproject.toml and command-line arguments.
     let mut configuration =
@@ -247,6 +233,9 @@ fn inner_main() -> Result<ExitCode> {
     if !cli.unfixable.is_empty() {
         configuration.unfixable = cli.unfixable;
     }
+    if let Some(format) = cli.format {
+        configuration.format = format;
+    }
     if let Some(line_length) = cli.line_length {
         configuration.line_length = line_length;
     }
@@ -279,6 +268,30 @@ fn inner_main() -> Result<ExitCode> {
     let fix_enabled: bool = configuration.fix;
     let settings = Settings::from_configuration(configuration, project_root.as_ref())?;
 
+    // If we're using JSON, override the log level.
+    let log_level = if matches!(settings.format, SerializationFormat::Json) {
+        LogLevel::Quiet
+    } else {
+        log_level
+    };
+    set_up_logging(&log_level)?;
+
+    // Now that we've inferred the appropriate log level, add some debug
+    // information.
+    match &project_root {
+        Some(path) => debug!("Found project root at: {:?}", path),
+        None => debug!("Unable to identify project root; assuming current directory..."),
+    };
+    match &pyproject {
+        Some(path) => debug!("Found pyproject.toml at: {:?}", path),
+        None => debug!("Unable to find pyproject.toml; using default settings..."),
+    };
+
+    if let Some(code) = cli.explain {
+        commands::explain(&code, settings.format)?;
+        return Ok(ExitCode::SUCCESS);
+    }
+
     if cli.show_files {
         commands::show_files(&cli.files, &settings);
         return Ok(ExitCode::SUCCESS);
@@ -291,24 +304,21 @@ fn inner_main() -> Result<ExitCode> {
         cache_enabled = false;
     }
 
-    let printer = Printer::new(&cli.format, &log_level);
+    let printer = Printer::new(&settings.format, &log_level);
     if cli.watch {
+        if settings.format != SerializationFormat::Text {
+            eprintln!("Warning: --format 'text' is used in watch mode.");
+        }
         if fix_enabled {
             eprintln!("Warning: --fix is not enabled in watch mode.");
         }
-
         if cli.add_noqa {
             eprintln!("Warning: --no-qa is not enabled in watch mode.");
         }
-
         if cli.autoformat {
             eprintln!("Warning: --autoformat is not enabled in watch mode.");
         }
 
-        if cli.format != SerializationFormat::Text {
-            eprintln!("Warning: --format 'text' is used in watch mode.");
-        }
-
         // Perform an initial run instantly.
         printer.clear_screen()?;
         printer.write_to_user("Starting linter in watch mode...\n");
diff --git a/src/printer.rs b/src/printer.rs
index 8623a77b1c..01ef8d3b05 100644
--- a/src/printer.rs
+++ b/src/printer.rs
@@ -4,7 +4,6 @@ use std::path::Path;
 use annotate_snippets::display_list::{DisplayList, FormatOptions};
 use annotate_snippets::snippet::{Annotation, AnnotationType, Slice, Snippet, SourceAnnotation};
 use anyhow::Result;
-use clap::ValueEnum;
 use colored::Colorize;
 use itertools::iterate;
 use rustpython_parser::ast::Location;
@@ -15,15 +14,9 @@ use crate::fs::relativize_path;
 use crate::linter::Diagnostics;
 use crate::logging::LogLevel;
 use crate::message::Message;
+use crate::settings::types::SerializationFormat;
 use crate::tell_user;
 
-#[derive(Clone, Copy, ValueEnum, PartialEq, Eq, Debug)]
-pub enum SerializationFormat {
-    Text,
-    Json,
-    Grouped,
-}
-
 #[derive(Serialize)]
 struct ExpandedMessage<'a> {
     kind: &'a CheckKind,
diff --git a/src/settings/configuration.rs b/src/settings/configuration.rs
index 4560fb6293..56704e0329 100644
--- a/src/settings/configuration.rs
+++ b/src/settings/configuration.rs
@@ -11,7 +11,7 @@ use regex::Regex;
 
 use crate::checks_gen::{CheckCodePrefix, CATEGORIES};
 use crate::settings::pyproject::load_options;
-use crate::settings::types::{FilePattern, PerFileIgnore, PythonVersion};
+use crate::settings::types::{FilePattern, PerFileIgnore, PythonVersion, SerializationFormat};
 use crate::{
     flake8_annotations, flake8_bugbear, flake8_quotes, flake8_tidy_imports, fs, isort, mccabe,
     pep8_naming,
@@ -27,6 +27,7 @@ pub struct Configuration {
     pub external: Vec<String>,
     pub fix: bool,
     pub fixable: Vec<CheckCodePrefix>,
+    pub format: SerializationFormat,
     pub ignore: Vec<CheckCodePrefix>,
     pub line_length: usize,
     pub per_file_ignores: Vec<PerFileIgnore>,
@@ -121,6 +122,7 @@ impl Configuration {
             fix: options.fix.unwrap_or_default(),
             fixable: options.fixable.unwrap_or_else(|| CATEGORIES.to_vec()),
             unfixable: options.unfixable.unwrap_or_default(),
+            format: options.format.unwrap_or(SerializationFormat::Text),
             ignore: options.ignore.unwrap_or_default(),
             line_length: options.line_length.unwrap_or(88),
             per_file_ignores: options
diff --git a/src/settings/mod.rs b/src/settings/mod.rs
index d06ca1590f..60b5d92504 100644
--- a/src/settings/mod.rs
+++ b/src/settings/mod.rs
@@ -15,7 +15,7 @@ use rustc_hash::FxHashSet;
 use crate::checks::CheckCode;
 use crate::checks_gen::{CheckCodePrefix, PrefixSpecificity};
 use crate::settings::configuration::Configuration;
-use crate::settings::types::{FilePattern, PerFileIgnore, PythonVersion};
+use crate::settings::types::{FilePattern, PerFileIgnore, PythonVersion, SerializationFormat};
 use crate::{
     flake8_annotations, flake8_bugbear, flake8_quotes, flake8_tidy_imports, fs, isort, mccabe,
     pep8_naming,
@@ -34,6 +34,7 @@ pub struct Settings {
     pub extend_exclude: GlobSet,
     pub external: BTreeSet<String>,
     pub fixable: FxHashSet<CheckCode>,
+    pub format: SerializationFormat,
     pub line_length: usize,
     pub per_file_ignores: Vec<(GlobMatcher, GlobMatcher, BTreeSet<CheckCode>)>,
     pub show_source: bool,
@@ -72,6 +73,7 @@ impl Settings {
             extend_exclude: resolve_globset(config.extend_exclude, project_root)?,
             external: BTreeSet::from_iter(config.external),
             fixable: resolve_codes(&config.fixable, &config.unfixable),
+            format: config.format,
             flake8_annotations: config.flake8_annotations,
             flake8_bugbear: config.flake8_bugbear,
             flake8_quotes: config.flake8_quotes,
@@ -91,12 +93,14 @@ impl Settings {
         Self {
             dummy_variable_rgx: Regex::new("^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$").unwrap(),
             enabled: FxHashSet::from_iter([check_code.clone()]),
-            fixable: FxHashSet::from_iter([check_code]),
             exclude: GlobSet::empty(),
             extend_exclude: GlobSet::empty(),
             external: BTreeSet::default(),
+            fixable: FxHashSet::from_iter([check_code]),
+            format: SerializationFormat::Text,
             line_length: 88,
             per_file_ignores: vec![],
+            show_source: false,
             src: vec![path_dedot::CWD.clone()],
             target_version: PythonVersion::Py310,
             flake8_annotations: flake8_annotations::settings::Settings::default(),
@@ -106,7 +110,6 @@ impl Settings {
             isort: isort::settings::Settings::default(),
             mccabe: mccabe::settings::Settings::default(),
             pep8_naming: pep8_naming::settings::Settings::default(),
-            show_source: false,
         }
     }
 
@@ -114,12 +117,14 @@ impl Settings {
         Self {
             dummy_variable_rgx: Regex::new("^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$").unwrap(),
             enabled: FxHashSet::from_iter(check_codes.clone()),
-            fixable: FxHashSet::from_iter(check_codes),
             exclude: GlobSet::empty(),
             extend_exclude: GlobSet::empty(),
             external: BTreeSet::default(),
+            fixable: FxHashSet::from_iter(check_codes),
+            format: SerializationFormat::Text,
             line_length: 88,
             per_file_ignores: vec![],
+            show_source: false,
             src: vec![path_dedot::CWD.clone()],
             target_version: PythonVersion::Py310,
             flake8_annotations: flake8_annotations::settings::Settings::default(),
@@ -129,7 +134,6 @@ impl Settings {
             isort: isort::settings::Settings::default(),
             mccabe: mccabe::settings::Settings::default(),
             pep8_naming: pep8_naming::settings::Settings::default(),
-            show_source: false,
         }
     }
 }
diff --git a/src/settings/options.rs b/src/settings/options.rs
index 40ac20d66e..57a83e74c0 100644
--- a/src/settings/options.rs
+++ b/src/settings/options.rs
@@ -4,7 +4,7 @@ use rustc_hash::FxHashMap;
 use serde::{Deserialize, Serialize};
 
 use crate::checks_gen::CheckCodePrefix;
-use crate::settings::types::PythonVersion;
+use crate::settings::types::{PythonVersion, SerializationFormat};
 use crate::{
     flake8_annotations, flake8_bugbear, flake8_quotes, flake8_tidy_imports, isort, mccabe,
     pep8_naming,
@@ -21,6 +21,7 @@ pub struct Options {
     pub external: Option<Vec<String>>,
     pub fix: Option<bool>,
     pub fixable: Option<Vec<CheckCodePrefix>>,
+    pub format: Option<SerializationFormat>,
     pub ignore: Option<Vec<CheckCodePrefix>>,
     pub line_length: Option<usize>,
     pub select: Option<Vec<CheckCodePrefix>>,
diff --git a/src/settings/pyproject.rs b/src/settings/pyproject.rs
index 4a3f6e25eb..1a25c6b2e9 100644
--- a/src/settings/pyproject.rs
+++ b/src/settings/pyproject.rs
@@ -148,6 +148,7 @@ mod tests {
                     show_source: None,
                     src: None,
                     target_version: None,
+                    format: None,
                     unfixable: None,
                     flake8_annotations: None,
                     flake8_bugbear: None,
@@ -186,6 +187,7 @@ line-length = 79
                     show_source: None,
                     src: None,
                     target_version: None,
+                    format: None,
                     unfixable: None,
                     flake8_annotations: None,
                     flake8_bugbear: None,
@@ -219,6 +221,7 @@ exclude = ["foo.py"]
                     ignore: None,
                     extend_ignore: None,
                     fixable: None,
+                    format: None,
                     unfixable: None,
                     per_file_ignores: None,
                     dummy_variable_rgx: None,
@@ -262,6 +265,7 @@ select = ["E501"]
                     show_source: None,
                     src: None,
                     target_version: None,
+                    format: None,
                     unfixable: None,
                     flake8_annotations: None,
                     flake8_bugbear: None,
@@ -301,6 +305,7 @@ ignore = ["E501"]
                     show_source: None,
                     src: None,
                     target_version: None,
+                    format: None,
                     unfixable: None,
                     flake8_annotations: None,
                     flake8_bugbear: None,
@@ -378,6 +383,7 @@ other-attribute = 1
                 ignore: None,
                 extend_ignore: None,
                 fixable: None,
+                format: None,
                 unfixable: None,
                 per_file_ignores: Some(FxHashMap::from_iter([(
                     "__init__.py".to_string(),
diff --git a/src/settings/types.rs b/src/settings/types.rs
index c6b80ddbf5..7a01b6b654 100644
--- a/src/settings/types.rs
+++ b/src/settings/types.rs
@@ -4,6 +4,7 @@ use std::path::{Path, PathBuf};
 use std::str::FromStr;
 
 use anyhow::{anyhow, Result};
+use clap::ValueEnum;
 use globset::{Glob, GlobSetBuilder};
 use serde::{de, Deserialize, Deserializer, Serialize};
 
@@ -141,3 +142,11 @@ impl FromStr for PatternPrefixPair {
         Ok(Self { pattern, prefix })
     }
 }
+
+#[derive(Clone, Copy, ValueEnum, PartialEq, Eq, Serialize, Deserialize, Debug)]
+#[serde(rename_all = "kebab-case")]
+pub enum SerializationFormat {
+    Text,
+    Json,
+    Grouped,
+}