diff --git a/src/taskgraph/main.py b/src/taskgraph/main.py
index e74da8a7d..994c8eff2 100644
--- a/src/taskgraph/main.py
+++ b/src/taskgraph/main.py
@@ -415,7 +415,10 @@ def show_kind_graph(options):
     "--tasks-regex",
     "--tasks",
     default=None,
-    help="only return tasks with labels matching this regular expression.",
+    help="only return tasks with labels matching this regular expression. "
+    "When --target-kind is given with --json/--yaml and this is omitted, it "
+    "defaults to a regex matching labels that begin with one of the target "
+    "kinds.",
 )
 @argument(
     "--exclude-key",
@@ -499,8 +502,25 @@ def show_taskgraph(options):
         )
         print(f"Generating {options['graph_attr']} @ {cur_rev}", file=sys.stderr)
 
+    target_kinds = options.get("target_kinds")
+    if (
+        target_kinds
+        and options.get("tasks_regex") is None
+        and options.get("format") in ("yaml", "json")
+    ):
+        options["tasks_regex"] = "^({})".format(
+            "|".join(re.escape(kind) for kind in target_kinds)
+        )
+        print(
+            "Filtering tasks with implied --tasks-regex "
+            f"'{options['tasks_regex']}' (derived from --target-kind). "
+            "Pass --tasks-regex explicitly to override, or '--tasks-regex .' "
+            "to disable filtering.",
+            file=sys.stderr,
+        )
+
     overrides = {
-        "target-kinds": options.get("target_kinds"),
+        "target-kinds": target_kinds,
     }
     parameters: list[Any[str, Parameters]] = options.pop("parameters")
     if not parameters:
diff --git a/test/test_main.py b/test/test_main.py
index 13c750d95..3110094e1 100644
--- a/test/test_main.py
+++ b/test/test_main.py
@@ -158,6 +158,62 @@ def test_tasks_regex(run_taskgraph, capsys):
     assert out.strip() == "_fake-t-1"
 
 
+def test_target_kind_implies_tasks_regex(run_taskgraph, capsys):
+    kinds = [
+        ("_fake", {"kind-dependencies": ["_dep"]}),
+        ("_dep", {"kind-dependencies": []}),
+        ("docker-image", {"kind-dependencies": []}),
+    ]
+    res = run_taskgraph(
+        ["full", "-Y", "-k", "_fake"],
+        kinds=kinds,
+        params={"target-kinds": ["_fake"]},
+    )
+    assert res == 0
+
+    out, err = capsys.readouterr()
+    assert "implied --tasks-regex '^(_fake)'" in err
+    assert "_fake-t-0" in out
+    assert "_dep-t-0" not in out
+
+
+def test_target_kind_no_implied_regex_for_labels(run_taskgraph, capsys):
+    kinds = [
+        ("_fake", {"kind-dependencies": ["_dep"]}),
+        ("_dep", {"kind-dependencies": []}),
+        ("docker-image", {"kind-dependencies": []}),
+    ]
+    res = run_taskgraph(
+        ["full", "-k", "_fake"],
+        kinds=kinds,
+        params={"target-kinds": ["_fake"]},
+    )
+    assert res == 0
+
+    out, err = capsys.readouterr()
+    assert "implied --tasks-regex" not in err
+    assert "_dep-t-0" in out
+
+
+def test_target_kind_explicit_regex_not_overridden(run_taskgraph, capsys):
+    kinds = [
+        ("_fake", {"kind-dependencies": ["_dep"]}),
+        ("_dep", {"kind-dependencies": []}),
+        ("docker-image", {"kind-dependencies": []}),
+    ]
+    res = run_taskgraph(
+        ["full", "-Y", "-k", "_fake", "--tasks-regex", "_dep-t-0"],
+        kinds=kinds,
+        params={"target-kinds": ["_fake"]},
+    )
+    assert res == 0
+
+    out, err = capsys.readouterr()
+    assert "implied --tasks-regex" not in err
+    assert "_dep-t-0" in out
+    assert "_fake-t-1" not in out
+
+
 def test_output_file(run_taskgraph, tmpdir):
     output_file = tmpdir.join("out.txt")
     assert not output_file.check()