diff --git a/CHANGELOG.md b/CHANGELOG.md
index a6fef33..40c9460 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,8 @@ The format is based on [Keep a Changelog].
   [HTML](https://en.wikipedia.org/wiki/HTML) and
   [CSS](https://www.google.com/search?q=css)
   ([#229])
+* [`python3-json`](https://docs.python.org/3/library/json.html#module-json.tool)
+  for JSON ([#257]).
 * [`robotidy`](https://robotidy.readthedocs.io) for Robot Framework files
   ([#263]).
 * [denofmt](https://docs.deno.com/runtime/manual/tools/formatter) for
@@ -24,6 +26,7 @@ The format is based on [Keep a Changelog].
   clojurescript, edn files. ([#271])
 
 [#229]: https://github.com/radian-software/apheleia/pull/229
+[#257]: https://github.com/radian-software/apheleia/pull/257
 [#260]: https://github.com/radian-software/apheleia/pull/260
 [#261]: https://github.com/radian-software/apheleia/pull/261
 [#263]: https://github.com/radian-software/apheleia/pull/263
diff --git a/apheleia-formatters.el b/apheleia-formatters.el
index 2446b0e..26c0a07 100644
--- a/apheleia-formatters.el
+++ b/apheleia-formatters.el
@@ -150,6 +150,9 @@
     (robotidy . ("robotidy" "--no-color" "-"
                  (apheleia-formatters-indent nil "--indent")
                  (apheleia-formatters-fill-column "--line-length")))
+    (python3-json
+     . ("python3" "-m" "json.tool"
+        (apheleia-formatters-indent "--tab" "--indent")))
     (rubocop . ("rubocop" "--stdin" filepath "--auto-correct"
                 "--stderr" "--format" "quiet" "--fail-level" "fatal"))
     (ruby-standard . ("standardrb" "--stdin" filepath "--fix" "--stderr"
diff --git a/apheleia-utils.el b/apheleia-utils.el
index 5e8b364..07a358b 100644
--- a/apheleia-utils.el
+++ b/apheleia-utils.el
@@ -49,6 +49,7 @@ always returns nil to defer to the formatter."
               (nxml-mode 'nxml-child-indent)
               (robot-mode 'robot-mode-basic-offset)
               (perl-mode 'perl-indent-level)
+              (python-mode 'python-indent-offset)
               (scss-mode 'css-indent-offset)
               (web-mode 'web-mode-indent-style)
               (tsx-ts-mode 'typescript-ts-mode-indent-offset)
diff --git a/test/formatters/installers/python3-json.bash b/test/formatters/installers/python3-json.bash
new file mode 100644
index 0000000..da920e3
--- /dev/null
+++ b/test/formatters/installers/python3-json.bash
@@ -0,0 +1 @@
+apt-get install -y python3
diff --git a/test/formatters/samplecode/python3-json/in.json b/test/formatters/samplecode/python3-json/in.json
new file mode 120000
index 0000000..599a1e2
--- /dev/null
+++ b/test/formatters/samplecode/python3-json/in.json
@@ -0,0 +1 @@
+../prettier-json/in.json
\ No newline at end of file
diff --git a/test/formatters/samplecode/python3-json/out.json b/test/formatters/samplecode/python3-json/out.json
new file mode 100644
index 0000000..6af7b82
--- /dev/null
+++ b/test/formatters/samplecode/python3-json/out.json
@@ -0,0 +1,19 @@
+{
+    "arrowParens": "always",
+    "bracketSpacing": true,
+    "embeddedLanguageFormatting": "auto",
+    "htmlWhitespaceSensitivity": "css",
+    "insertPragma": false,
+    "jsxBracketSameLine": false,
+    "jsxSingleQuote": false,
+    "printWidth": 80,
+    "proseWrap": "preserve",
+    "quoteProps": "as-needed",
+    "requirePragma": false,
+    "semi": true,
+    "singleQuote": false,
+    "tabWidth": 2,
+    "trailingComma": "es5",
+    "useTabs": false,
+    "vueIndentScriptAndStyle": false
+}