diff --git a/src/python/pants/backend/pants_info/list_target_types.py b/src/python/pants/backend/pants_info/list_target_types.py
index c1056daae45..b0b3652b250 100644
--- a/src/python/pants/backend/pants_info/list_target_types.py
+++ b/src/python/pants/backend/pants_info/list_target_types.py
@@ -1,9 +1,11 @@
 # Copyright 2020 Pants project contributors (see CONTRIBUTORS.md).
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
+import dataclasses
+import json
 import textwrap
 from dataclasses import dataclass
-from typing import Generic, Optional, Sequence, Type, cast, get_type_hints
+from typing import Any, Dict, Generic, Optional, Sequence, Type, cast, get_type_hints
 
 from pants.core.util_rules.pants_bin import PantsBin
 from pants.engine.console import Console
@@ -44,11 +46,21 @@ def register_options(cls, register):
             metavar="<target_type>",
             help="List all of the target type's registered fields.",
         )
+        register(
+            "--all",
+            type=bool,
+            default=False,
+            help="List all target types with their full descriptions and fields as JSON.",
+        )
 
     @property
     def details(self) -> Optional[str]:
         return cast(Optional[str], self.options.details)
 
+    @property
+    def all(self) -> bool:
+        return cast(bool, self.options.all)
+
 
 class TargetTypes(Goal):
     subsystem_cls = TargetTypesSubsystem
@@ -99,29 +111,26 @@ def create(cls, field: Type[Field]) -> "FieldInfo":
         # helper class like `StringField`. This is a quirk of this heuristic and it's not
         # intentional since these core `Field` types have documentation oriented to the custom
         # `Field` author and not the end user filling in fields in a BUILD file target.
-        description = (
-            get_docstring(
-                field,
-                flatten=True,
-                fallback_to_ancestors=True,
-                ignored_ancestors={
-                    *Field.mro(),
-                    AsyncField,
-                    PrimitiveField,
-                    BoolField,
-                    DictStringToStringField,
-                    DictStringToStringSequenceField,
-                    FloatField,
-                    Generic,  # type: ignore[arg-type]
-                    IntField,
-                    ScalarField,
-                    SequenceField,
-                    StringField,
-                    StringOrStringSequenceField,
-                    StringSequenceField,
-                },
-            )
-            or ""
+        description = get_docstring(
+            field,
+            flatten=True,
+            fallback_to_ancestors=True,
+            ignored_ancestors={
+                *Field.mro(),
+                AsyncField,
+                PrimitiveField,
+                BoolField,
+                DictStringToStringField,
+                DictStringToStringSequenceField,
+                FloatField,
+                Generic,  # type: ignore[arg-type]
+                IntField,
+                ScalarField,
+                SequenceField,
+                StringField,
+                StringOrStringSequenceField,
+                StringSequenceField,
+            },
         )
         if issubclass(field, PrimitiveField):
             raw_value_type = get_type_hints(field.compute_value)["raw_value"]
@@ -152,7 +161,9 @@ def create(cls, field: Type[Field]) -> "FieldInfo":
             description=description,
             type_hint=type_hint,
             required=field.required,
-            default=repr(field.default) if not field.required else None,
+            default=(
+                repr(field.default) if (not field.required and field.default is not None) else None
+            ),
         )
 
     def format_for_cli(self, console: Console) -> str:
@@ -162,9 +173,14 @@ def format_for_cli(self, console: Console) -> str:
         type_info = console.cyan(f"{indent}type: {self.type_hint}, {required_or_default}")
         lines = [field_alias, type_info]
         if self.description:
-            lines.extend(f"{indent}{line}" for line in textwrap.wrap(self.description, 80))
+            lines.extend(f"{indent}{line}" for line in textwrap.wrap(self.description or "", 80))
         return "\n".join(f"{indent}{line}" for line in lines)
 
+    def as_dict(self) -> Dict[str, Any]:
+        d = dataclasses.asdict(self)
+        del d["alias"]
+        return d
+
 
 @dataclass(frozen=True)
 class VerboseTargetInfo:
@@ -201,6 +217,12 @@ def format_for_cli(self, console: Console) -> str:
         )
         return "\n".join(output).rstrip()
 
+    def as_dict(self) -> Dict[str, Any]:
+        return {
+            "description": self.description,
+            "fields": {f.alias: f.as_dict() for f in self.fields},
+        }
+
 
 @goal_rule
 def list_target_types(
@@ -211,7 +233,16 @@ def list_target_types(
     pants_bin: PantsBin,
 ) -> TargetTypes:
     with target_types_subsystem.line_oriented(console) as print_stdout:
-        if target_types_subsystem.details:
+        if target_types_subsystem.all:
+            all_target_types = {
+                alias: VerboseTargetInfo.create(
+                    target_type, union_membership=union_membership
+                ).as_dict()
+                for alias, target_type in registered_target_types.aliases_to_types.items()
+                if not alias.startswith("_")
+            }
+            print_stdout(json.dumps(all_target_types, sort_keys=True, indent=4))
+        elif target_types_subsystem.details:
             alias = target_types_subsystem.details
             target_type = registered_target_types.aliases_to_types.get(alias)
             if target_type is None:
diff --git a/src/python/pants/backend/pants_info/list_target_types_test.py b/src/python/pants/backend/pants_info/list_target_types_test.py
index 8752ee12272..1c81f54d312 100644
--- a/src/python/pants/backend/pants_info/list_target_types_test.py
+++ b/src/python/pants/backend/pants_info/list_target_types_test.py
@@ -1,6 +1,7 @@
 # Copyright 2020 Pants project contributors (see CONTRIBUTORS.md).
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
+import json
 from enum import Enum
 from textwrap import dedent
 from typing import Optional, cast
@@ -71,7 +72,10 @@ class FortranBinary(Target):
 
 
 def run_goal(
-    *, union_membership: Optional[UnionMembership] = None, details_target: Optional[str] = None
+    *,
+    union_membership: Optional[UnionMembership] = None,
+    details_target: Optional[str] = None,
+    all: bool = False
 ) -> str:
     console = MockConsole(use_colors=False)
     run_rule_with_mocks(
@@ -80,7 +84,7 @@ def run_goal(
             RegisteredTargetTypes.create([FortranBinary, FortranLibrary, FortranTests]),
             union_membership or UnionMembership({}),
             create_goal_subsystem(
-                TargetTypesSubsystem, sep="\\n", output_file=None, details=details_target
+                TargetTypesSubsystem, sep="\\n", output_file=None, details=details_target, all=all
             ),
             console,
             PantsBin(name="./BNF"),
@@ -89,7 +93,7 @@ def run_goal(
     return cast(str, console.stdout.getvalue())
 
 
-def test_list_all() -> None:
+def test_list_all_abbreviated() -> None:
     stdout = run_goal()
     assert stdout == dedent(
         """\
@@ -110,6 +114,54 @@ def test_list_all() -> None:
     )
 
 
+def test_list_all_json() -> None:
+    stdout = run_goal(all=True)
+    fortran_version = {
+        "default": None,
+        "description": None,
+        "required": False,
+        "type_hint": "str | None",
+    }
+    assert json.loads(stdout) == {
+        "fortran_binary": {
+            "description": None,
+            "fields": {
+                "archive_format": {
+                    "default": "'.tgz'",
+                    "description": None,
+                    "required": False,
+                    "type_hint": "'.tar' | '.tgz' | None",
+                },
+                "error_behavior": {
+                    "default": None,
+                    "description": None,
+                    "required": True,
+                    "type_hint": "'error' | 'ignore' | 'warn'",
+                },
+                "fortran_version": fortran_version,
+            },
+        },
+        "fortran_library": {
+            "description": "A library of Fortran code.",
+            "fields": {"fortran_version": fortran_version},
+        },
+        "fortran_tests": {
+            "description": (
+                "Tests for Fortran code.\n\nThis assumes that you use the FRUIT test framework."
+            ),
+            "fields": {
+                "fortran_version": fortran_version,
+                "timeout": {
+                    "default": None,
+                    "description": "The number of seconds to run before timing out.",
+                    "required": False,
+                    "type_hint": "int | None",
+                },
+            },
+        },
+    }
+
+
 def test_list_single() -> None:
     class CustomField(BoolField):
         """My custom field!