diff --git a/src/sentry/options/defaults.py b/src/sentry/options/defaults.py
index fd005cc694decb..16ef76a984efff 100644
--- a/src/sentry/options/defaults.py
+++ b/src/sentry/options/defaults.py
@@ -655,6 +655,13 @@
     flags=FLAG_AUTOMATOR_MODIFIABLE,
 )
 
+register(
+    "relay.objectstore-attachments.sample-rate",
+    type=Float,
+    default=0.0,
+    flags=FLAG_AUTOMATOR_MODIFIABLE,
+)
+
 # Analytics
 register("analytics.backend", default="noop", flags=FLAG_NOSTORE)
 register("analytics.options", default={}, flags=FLAG_NOSTORE)
diff --git a/src/sentry/relay/globalconfig.py b/src/sentry/relay/globalconfig.py
index bccea324d4eeb0..ab201e09e2846f 100644
--- a/src/sentry/relay/globalconfig.py
+++ b/src/sentry/relay/globalconfig.py
@@ -25,6 +25,7 @@
     "relay.sessions-eap.rollout-rate",
     "relay.span-normalization.allowed_hosts",
     "relay.drop-transaction-attachments",
+    "relay.objectstore-attachments.sample-rate",
 ]
 
 
diff --git a/tests/sentry/api/endpoints/test_relay_globalconfig_v3.py b/tests/sentry/api/endpoints/test_relay_globalconfig_v3.py
index edd90a47ca9a3b..f471f8e7be654b 100644
--- a/tests/sentry/api/endpoints/test_relay_globalconfig_v3.py
+++ b/tests/sentry/api/endpoints/test_relay_globalconfig_v3.py
@@ -42,6 +42,7 @@ def inner(version, global_):
         "relay.span-usage-metric": True,
         "relay.cardinality-limiter.mode": "passive",
         "relay.sessions-eap.rollout-rate": 1.0,
+        "relay.objectstore-attachments.sample-rate": 1.0,
         "relay.kafka.span-v2.sample-rate": 1.0,
         "relay.metric-bucket-distribution-encodings": {
             "custom": "array",