diff --git a/sentry_sdk/scope.py b/sentry_sdk/scope.py
index a643cfa9c5..28fe89febe 100644
--- a/sentry_sdk/scope.py
+++ b/sentry_sdk/scope.py
@@ -33,6 +33,7 @@
     capture_internal_exception,
     capture_internal_exceptions,
     ContextVar,
+    datetime_from_isoformat,
     disable_capture_event,
     event_from_exception,
     exc_info_from_error,
@@ -1264,7 +1265,7 @@ def _apply_breadcrumbs_to_event(self, event, hint, options):
         try:
             for crumb in event["breadcrumbs"]["values"]:
                 if isinstance(crumb["timestamp"], str):
-                    crumb["timestamp"] = datetime.fromisoformat(crumb["timestamp"])
+                    crumb["timestamp"] = datetime_from_isoformat(crumb["timestamp"])
 
             event["breadcrumbs"]["values"].sort(key=lambda crumb: crumb["timestamp"])
         except Exception as err:
diff --git a/sentry_sdk/utils.py b/sentry_sdk/utils.py
index 8b45f555ae..16dfd9c4fa 100644
--- a/sentry_sdk/utils.py
+++ b/sentry_sdk/utils.py
@@ -1929,3 +1929,28 @@ def _serialize_span_attribute(value):
             return str(value)
         except Exception:
             return None
+
+
+ISO_TZ_SEPARATORS = frozenset(("+", "-"))
+
+
+def datetime_from_isoformat(value):
+    # type: (str) -> datetime
+    try:
+        result = datetime.fromisoformat(value)
+    except (AttributeError, ValueError):
+        # py 3.6
+        timestamp_format = (
+            "%Y-%m-%dT%H:%M:%S.%f" if "." in value else "%Y-%m-%dT%H:%M:%S"
+        )
+        if value.endswith("Z"):
+            value = value[:-1] + "+0000"
+
+        if value[-6] in ISO_TZ_SEPARATORS:
+            timestamp_format += "%z"
+            value = value[:-3] + value[-2:]
+        elif value[-5] in ISO_TZ_SEPARATORS:
+            timestamp_format += "%z"
+
+        result = datetime.strptime(value, timestamp_format)
+    return result.astimezone(timezone.utc)
diff --git a/tests/test_basics.py b/tests/test_basics.py
index 749d31d7d3..3c05f9848a 100644
--- a/tests/test_basics.py
+++ b/tests/test_basics.py
@@ -32,7 +32,7 @@
 from sentry_sdk.integrations.logging import LoggingIntegration
 from sentry_sdk.integrations.stdlib import StdlibIntegration
 from sentry_sdk.scope import add_global_event_processor
-from sentry_sdk.utils import get_sdk_name, reraise
+from sentry_sdk.utils import datetime_from_isoformat, get_sdk_name, reraise
 from sentry_sdk.tracing_utils import has_tracing_enabled
 
 
@@ -348,7 +348,7 @@ def test_breadcrumb_ordering(sentry_init, capture_events):
 
     assert len(event["breadcrumbs"]["values"]) == len(timestamps)
     timestamps_from_event = [
-        datetime.fromisoformat(x["timestamp"]) for x in event["breadcrumbs"]["values"]
+        datetime_from_isoformat(x["timestamp"]) for x in event["breadcrumbs"]["values"]
     ]
     assert timestamps_from_event == sorted(timestamps)
 
@@ -389,7 +389,7 @@ def test_breadcrumb_ordering_different_types(sentry_init, capture_events):
 
     assert len(event["breadcrumbs"]["values"]) == len(timestamps)
     timestamps_from_event = [
-        datetime.fromisoformat(x["timestamp"]) for x in event["breadcrumbs"]["values"]
+        datetime_from_isoformat(x["timestamp"]) for x in event["breadcrumbs"]["values"]
     ]
     assert timestamps_from_event == sorted(timestamps)
 
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 5011662f05..2eab252573 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -12,6 +12,7 @@
 from sentry_sdk.utils import (
     Components,
     Dsn,
+    datetime_from_isoformat,
     env_to_bool,
     format_timestamp,
     get_current_thread_meta,
@@ -933,3 +934,52 @@ def __str__(self):
 )
 def test_serialize_span_attribute(value, result):
     assert _serialize_span_attribute(value) == result
+
+
+@pytest.mark.parametrize(
+    ("input_str", "expected_output"),
+    (
+        (
+            "2021-01-01T00:00:00.000000Z",
+            datetime(2021, 1, 1, tzinfo=timezone.utc),
+        ),  # UTC time
+        (
+            "2021-01-01T00:00:00.000000",
+            datetime(2021, 1, 1, tzinfo=datetime.now().astimezone().tzinfo),
+        ),  # No TZ -- assume UTC
+        (
+            "2021-01-01T00:00:00Z",
+            datetime(2021, 1, 1, tzinfo=timezone.utc),
+        ),  # UTC - No milliseconds
+        (
+            "2021-01-01T00:00:00.000000+00:00",
+            datetime(2021, 1, 1, tzinfo=timezone.utc),
+        ),
+        (
+            "2021-01-01T00:00:00.000000-00:00",
+            datetime(2021, 1, 1, tzinfo=timezone.utc),
+        ),
+        (
+            "2021-01-01T00:00:00.000000+0000",
+            datetime(2021, 1, 1, tzinfo=timezone.utc),
+        ),
+        (
+            "2021-01-01T00:00:00.000000-0000",
+            datetime(2021, 1, 1, tzinfo=timezone.utc),
+        ),
+        (
+            "2020-12-31T00:00:00.000000+02:00",
+            datetime(2020, 12, 31, tzinfo=timezone(timedelta(hours=2))),
+        ),  # UTC+2 time
+        (
+            "2020-12-31T00:00:00.000000-0200",
+            datetime(2020, 12, 31, tzinfo=timezone(timedelta(hours=-2))),
+        ),  # UTC-2 time
+        (
+            "2020-12-31T00:00:00-0200",
+            datetime(2020, 12, 31, tzinfo=timezone(timedelta(hours=-2))),
+        ),  # UTC-2 time - no milliseconds
+    ),
+)
+def test_datetime_from_isoformat(input_str, expected_output):
+    assert datetime_from_isoformat(input_str) == expected_output, input_str
\ No newline at end of file