diff --git a/airbyte-lib/pyproject.toml b/airbyte-lib/pyproject.toml
index 203c446552eed..d1bdb3049c0cc 100644
--- a/airbyte-lib/pyproject.toml
+++ b/airbyte-lib/pyproject.toml
@@ -56,7 +56,10 @@ requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"
 
 [tool.pytest.ini_options]
-# addopts = "--mypy"  # FIXME: This sometimes blocks test discovery and execution
+markers = [
+    "slow: marks tests as slow (deselect with '-m \"not slow\"')",
+    "requires_creds: marks a test as requiring credentials (skip when secrets unavailable)"
+]
 
 [tool.ruff.pylint]
 max-args = 8  # Relaxed from default of 5
diff --git a/airbyte-lib/tests/conftest.py b/airbyte-lib/tests/conftest.py
index 64a3b83431b70..0824d77f3eb8e 100644
--- a/airbyte-lib/tests/conftest.py
+++ b/airbyte-lib/tests/conftest.py
@@ -44,7 +44,9 @@ def pytest_collection_modifyitems(items: list[Item]) -> None:
     'integration' tests because 'u' comes after 'i' alphabetically.
     """
     def test_priority(item: Item) -> int:
-        if 'lint_tests' in str(item.fspath):
+        if item.get_closest_marker(name="slow"):
+            return 9  # slow tests have the lowest priority
+        elif 'lint_tests' in str(item.fspath):
             return 1  # lint tests have high priority
         elif 'unit_tests' in str(item.fspath):
             return 2  # unit tests have highest priority
diff --git a/airbyte-lib/tests/integration_tests/test_snowflake_cache.py b/airbyte-lib/tests/integration_tests/test_snowflake_cache.py
index be8aacd8decc1..4ac08f4bebe3b 100644
--- a/airbyte-lib/tests/integration_tests/test_snowflake_cache.py
+++ b/airbyte-lib/tests/integration_tests/test_snowflake_cache.py
@@ -98,6 +98,8 @@ def snowflake_cache(snowflake_config) -> Generator[caches.SnowflakeCache, None,
 # Uncomment this line if you want to see performance trace logs.
 # You can render perf traces using the viztracer CLI or the VS Code VizTracer Extension.
 #@viztracer.trace_and_save(output_dir=".pytest_cache/snowflake_trace/")
+@pytest.mark.requires_creds
+@pytest.mark.slow
 def test_faker_read_to_snowflake(
     source_faker_seed_a: ab.Source,
     snowflake_cache: ab.SnowflakeCache,
@@ -109,6 +111,8 @@ def test_faker_read_to_snowflake(
     assert len(list(result.cache.streams["users"])) == FAKER_SCALE_A
 
 
+@pytest.mark.requires_creds
+@pytest.mark.slow
 def test_replace_strategy(
     source_faker_seed_a: ab.Source,
     snowflake_cache: ab.SnowflakeCache,
@@ -121,6 +125,8 @@ def test_replace_strategy(
     assert len(list(result.cache.streams["users"])) == FAKER_SCALE_A
 
 
+@pytest.mark.requires_creds
+@pytest.mark.slow
 def test_merge_strategy(
     source_faker_seed_a: ab.Source,
     source_faker_seed_b: ab.Source,
diff --git a/airbyte-lib/tests/integration_tests/test_source_faker_integration.py b/airbyte-lib/tests/integration_tests/test_source_faker_integration.py
index 22e16b6ef0afc..244c52f0e901e 100644
--- a/airbyte-lib/tests/integration_tests/test_source_faker_integration.py
+++ b/airbyte-lib/tests/integration_tests/test_source_faker_integration.py
@@ -141,6 +141,7 @@ def test_faker_pks(
     assert read_result.cache._get_primary_keys("purchases") == ["id"]
 
 
+@pytest.mark.slow
 def test_replace_strategy(
     source_faker_seed_a: ab.Source,
     all_cache_types: ab.DuckDBCache,
@@ -155,6 +156,7 @@ def test_replace_strategy(
             assert len(list(result.cache.streams["purchases"])) == FAKER_SCALE_A
 
 
+@pytest.mark.slow
 def test_append_strategy(
     source_faker_seed_a: ab.Source,
     all_cache_types: ab.DuckDBCache,
@@ -167,6 +169,7 @@ def test_append_strategy(
             assert len(list(result.cache.streams["purchases"])) == FAKER_SCALE_A * iteration
 
 
+@pytest.mark.slow
 @pytest.mark.parametrize("strategy", ["merge", "auto"])
 def test_merge_strategy(
     strategy: str,
diff --git a/airbyte-lib/tests/integration_tests/test_source_test_fixture.py b/airbyte-lib/tests/integration_tests/test_source_test_fixture.py
index 6fc9d04bc0470..dadc7b12da72c 100644
--- a/airbyte-lib/tests/integration_tests/test_source_test_fixture.py
+++ b/airbyte-lib/tests/integration_tests/test_source_test_fixture.py
@@ -688,6 +688,8 @@ def test_sync_to_postgres(new_pg_cache_config: PostgresCacheConfig, expected_tes
             check_dtype=False,
         )
 
+@pytest.mark.slow
+@pytest.mark.requires_creds
 def test_sync_to_snowflake(snowflake_config: SnowflakeCacheConfig, expected_test_stream_data: dict[str, list[dict[str, str | int]]]):
     source = ab.get_source("source-test", config={"apiKey": "test"})
     source.select_all_streams()