diff --git a/newsfragments/3275.bugfix.rst b/newsfragments/3275.bugfix.rst
new file mode 100644
index 0000000000..b418b26d76
--- /dev/null
+++ b/newsfragments/3275.bugfix.rst
@@ -0,0 +1 @@
+Handle unwrapping SystemExit/KeyboardInterrupt exception gracefully in utility function ``raise_single_exception_from_group`` that reraises last exception from group.
diff --git a/src/trio/_tests/test_util.py b/src/trio/_tests/test_util.py
index 4182ba5db4..3a57b9cf21 100644
--- a/src/trio/_tests/test_util.py
+++ b/src/trio/_tests/test_util.py
@@ -323,25 +323,32 @@ async def test_raise_single_exception_from_group() -> None:
         [
             ValueError("foo"),
             ValueError("bar"),
-            KeyboardInterrupt("this exc doesn't get reraised"),
+            KeyboardInterrupt("preserve error msg"),
         ],
     )
-    with pytest.raises(KeyboardInterrupt, match=r"^$") as excinfo:
+    with pytest.raises(
+        KeyboardInterrupt,
+        match=r"^preserve error msg$",
+    ) as excinfo:
         raise_single_exception_from_group(eg_ki)
+
     assert excinfo.value.__cause__ is eg_ki
     assert excinfo.value.__context__ is None
 
-    # and same for SystemExit
+    # and same for SystemExit but verify code too
     systemexit_ki = BaseExceptionGroup(
         "",
         [
             ValueError("foo"),
             ValueError("bar"),
-            SystemExit("this exc doesn't get reraised"),
+            SystemExit(2),
         ],
     )
-    with pytest.raises(SystemExit, match=r"^$") as excinfo:
+
+    with pytest.raises(SystemExit) as excinfo:
         raise_single_exception_from_group(systemexit_ki)
+
+    assert excinfo.value.code == 2
     assert excinfo.value.__cause__ is systemexit_ki
     assert excinfo.value.__context__ is None
 
diff --git a/src/trio/_util.py b/src/trio/_util.py
index 106423e2aa..54d324cab3 100644
--- a/src/trio/_util.py
+++ b/src/trio/_util.py
@@ -398,7 +398,7 @@ def raise_single_exception_from_group(
     # immediately bail out if there's any KI or SystemExit
     for e in eg.exceptions:
         if isinstance(e, (KeyboardInterrupt, SystemExit)):
-            raise type(e) from eg
+            raise type(e)(*e.args) from eg
 
     cancelled_exception: trio.Cancelled | None = None
     noncancelled_exception: BaseException | None = None