diff --git a/src/sentry/conf/server.py b/src/sentry/conf/server.py
index 0622941272bafb..c4110a2b0290a3 100644
--- a/src/sentry/conf/server.py
+++ b/src/sentry/conf/server.py
@@ -2639,6 +2639,7 @@ def build_cdc_postgres_init_db_volume(settings):
 KAFKA_INGEST_REPLAY_EVENTS = "ingest-replay-events"
 KAFKA_INGEST_REPLAYS_RECORDINGS = "ingest-replay-recordings"
 KAFKA_INGEST_OCCURRENCES = "ingest-occurrences"
+KAFKA_INGEST_MONITORS = "ingest-monitors"
 KAFKA_REGION_TO_CONTROL = "region-to-control"
 KAFKA_EVENTSTREAM_GENERIC = "generic-events"
 
@@ -2687,6 +2688,7 @@ def build_cdc_postgres_init_db_volume(settings):
     KAFKA_INGEST_REPLAY_EVENTS: {"cluster": "default"},
     KAFKA_INGEST_REPLAYS_RECORDINGS: {"cluster": "default"},
     KAFKA_INGEST_OCCURRENCES: {"cluster": "default"},
+    KAFKA_INGEST_MONITORS: {"cluster": "default"},
     # Metrics Testing Topics
     KAFKA_SNUBA_GENERICS_METRICS_CS: {"cluster": "default"},
     # Region to Control Silo messaging - eg UserIp and AuditLog
diff --git a/src/sentry/models/monitorcheckin.py b/src/sentry/models/monitorcheckin.py
index 56a654dd589ced..a83aeb2760eaf9 100644
--- a/src/sentry/models/monitorcheckin.py
+++ b/src/sentry/models/monitorcheckin.py
@@ -59,9 +59,10 @@ class MonitorCheckIn(Model):
     duration = BoundedPositiveIntegerField(null=True)
     date_added = models.DateTimeField(default=timezone.now)
     date_updated = models.DateTimeField(default=timezone.now)
-    objects = BaseManager(cache_fields=("guid",))
     attachment_id = BoundedBigIntegerField(null=True)
 
+    objects = BaseManager(cache_fields=("guid",))
+
     class Meta:
         app_label = "sentry"
         db_table = "sentry_monitorcheckin"
diff --git a/src/sentry/monitors/consumers/__init__.py b/src/sentry/monitors/consumers/__init__.py
new file mode 100644
index 00000000000000..ec56576011d905
--- /dev/null
+++ b/src/sentry/monitors/consumers/__init__.py
@@ -0,0 +1,58 @@
+from __future__ import annotations
+
+from typing import Any, MutableMapping
+
+from arroyo import Topic
+from arroyo.backends.kafka.configuration import build_kafka_consumer_configuration
+from arroyo.backends.kafka.consumer import KafkaConsumer, KafkaPayload
+from arroyo.commit import ONCE_PER_SECOND
+from arroyo.processing.processor import StreamProcessor
+from django.conf import settings
+
+from sentry.monitors.consumers.check_in import StoreMonitorCheckInStrategyFactory
+from sentry.utils import kafka_config
+from sentry.utils.batching_kafka_consumer import create_topics
+
+
+def get_monitor_check_ins_consumer(
+    topic: str,
+    group_id: str,
+    auto_offset_reset: str,
+    strict_offset_reset: bool,
+    force_topic: str | None,
+    force_cluster: str | None,
+) -> StreamProcessor[KafkaPayload]:
+    topic = force_topic or topic
+    consumer_config = get_config(
+        topic,
+        group_id,
+        auto_offset_reset=auto_offset_reset,
+        strict_offset_reset=strict_offset_reset,
+        force_cluster=force_cluster,
+    )
+    consumer = KafkaConsumer(consumer_config)
+    return StreamProcessor(
+        consumer=consumer,
+        topic=Topic(topic),
+        processor_factory=StoreMonitorCheckInStrategyFactory(),
+        commit_policy=ONCE_PER_SECOND,
+    )
+
+
+def get_config(
+    topic: str,
+    group_id: str,
+    auto_offset_reset: str,
+    strict_offset_reset: bool,
+    force_cluster: str | None,
+) -> MutableMapping[str, Any]:
+    cluster_name: str = force_cluster or settings.KAFKA_TOPICS[topic]["cluster"]
+    create_topics(cluster_name, [topic])
+    return build_kafka_consumer_configuration(
+        kafka_config.get_kafka_consumer_cluster_options(
+            cluster_name,
+        ),
+        group_id=group_id,
+        auto_offset_reset=auto_offset_reset,
+        strict_offset_reset=strict_offset_reset,
+    )
diff --git a/src/sentry/monitors/consumers/check_in.py b/src/sentry/monitors/consumers/check_in.py
new file mode 100644
index 00000000000000..0627970002e6dc
--- /dev/null
+++ b/src/sentry/monitors/consumers/check_in.py
@@ -0,0 +1,112 @@
+import datetime
+import logging
+from typing import Mapping
+
+import msgpack
+from arroyo.backends.kafka.consumer import KafkaPayload
+from arroyo.processing.strategies.abstract import ProcessingStrategy, ProcessingStrategyFactory
+from arroyo.processing.strategies.commit import CommitOffsets
+from arroyo.processing.strategies.run_task import RunTask
+from arroyo.types import Commit, Message, Partition
+from django.db import transaction
+
+from sentry.models import CheckInStatus, Monitor, MonitorCheckIn, MonitorStatus, Project
+from sentry.signals import first_cron_checkin_received, first_cron_monitor_created
+from sentry.utils import json
+from sentry.utils.dates import to_datetime
+
+logger = logging.getLogger(__name__)
+
+
+def process_message(message: Message[KafkaPayload]) -> None:
+    wrapper = msgpack.unpackb(message.payload.value)
+
+    params = json.loads(wrapper["payload"])
+    start_time = to_datetime(float(wrapper["start_time"]))
+    project_id = int(wrapper["project_id"])
+
+    # TODO: Same as the check-in endpoints. Keep in sync or factor out.
+    try:
+        with transaction.atomic():
+            try:
+                monitor = Monitor.objects.select_for_update().get(
+                    guid=params["monitor_id"], project_id=project_id
+                )
+            except Monitor.DoesNotExist:
+                logger.debug("monitor does not exist: %s", params["monitor_id"])
+                return
+
+            status = getattr(CheckInStatus, params["status"].upper())
+            duration = int(params["duration"]) if params.get("duration") is not None else None
+
+            try:
+                check_in = MonitorCheckIn.objects.select_for_update().get(
+                    guid=params["check_in_id"],
+                    project_id=project_id,
+                    monitor=monitor,
+                )
+
+                if duration is None:
+                    duration = int((start_time - check_in.date_added).total_seconds() * 1000)
+
+                check_in.update(status=status, duration=duration)
+
+            except MonitorCheckIn.DoesNotExist:
+                # Infer the original start time of the check-in from the duration.
+                # Note that the clock of this worker may be off from what Relay is reporting.
+                date_added = start_time
+                if duration is not None:
+                    date_added -= datetime.timedelta(seconds=duration)
+
+                check_in = MonitorCheckIn.objects.create(
+                    project_id=project_id,
+                    monitor=monitor,
+                    guid=params["check_in_id"],
+                    duration=duration,
+                    status=status,
+                    date_added=date_added,
+                    date_updated=start_time,
+                )
+
+                project = Project.objects.get_from_cache(id=project_id)
+                if not project.flags.has_cron_checkins:
+                    # Backfill users that already have cron monitors
+                    if not project.flags.has_cron_monitors:
+                        first_cron_monitor_created.send_robust(
+                            project=project, user=None, sender=Project
+                        )
+
+                    first_cron_checkin_received.send_robust(
+                        project=project, monitor_id=str(monitor.guid), sender=Project
+                    )
+
+            if check_in.status == CheckInStatus.ERROR and monitor.status != MonitorStatus.DISABLED:
+                monitor.mark_failed(start_time)
+                return
+
+            monitor_params = {
+                "last_checkin": start_time,
+                "next_checkin": monitor.get_next_scheduled_checkin(start_time),
+            }
+
+            if check_in.status == CheckInStatus.OK and monitor.status != MonitorStatus.DISABLED:
+                monitor_params["status"] = MonitorStatus.OK
+
+            Monitor.objects.filter(id=monitor.id).exclude(last_checkin__gt=start_time).update(
+                **monitor_params
+            )
+    except Exception:
+        # Skip this message and continue processing in the consumer.
+        logger.exception("Failed to process check-in", exc_info=True)
+
+
+class StoreMonitorCheckInStrategyFactory(ProcessingStrategyFactory[KafkaPayload]):
+    def create_with_partitions(
+        self,
+        commit: Commit,
+        partitions: Mapping[Partition, int],
+    ) -> ProcessingStrategy[KafkaPayload]:
+        return RunTask(
+            function=process_message,
+            next_step=CommitOffsets(commit),
+        )
diff --git a/src/sentry/runner/commands/devserver.py b/src/sentry/runner/commands/devserver.py
index 91fd6d29ddbe1b..cb2188feaafc15 100644
--- a/src/sentry/runner/commands/devserver.py
+++ b/src/sentry/runner/commands/devserver.py
@@ -27,6 +27,9 @@
     "--no-strict-offset-reset",
 ]
 
+# NOTE: These do NOT start automatically. Add your daemon to the `daemons` list
+# in `devserver()` like so:
+#     daemons += [_get_daemon("my_new_daemon")]
 _DEFAULT_DAEMONS = {
     "worker": ["sentry", "run", "worker", "-c", "1", "--autoreload"],
     "cron": ["sentry", "run", "cron", "--autoreload"],
@@ -96,6 +99,7 @@
     ],
     "metrics-billing": ["sentry", "run", "billing-metrics-consumer", "--no-strict-offset-reset"],
     "profiles": ["sentry", "run", "ingest-profiles", "--no-strict-offset-reset"],
+    "monitors": ["sentry", "run", "ingest-monitors", "--no-strict-offset-reset"],
 }
 
 
@@ -324,7 +328,7 @@ def devserver(
             ]
 
     if settings.SENTRY_USE_RELAY:
-        daemons += [_get_daemon("ingest")]
+        daemons += [_get_daemon("ingest"), _get_daemon("monitors")]
 
         if settings.SENTRY_USE_PROFILING:
             daemons += [_get_daemon("profiles")]
diff --git a/src/sentry/runner/commands/run.py b/src/sentry/runner/commands/run.py
index 96a193e37b2e8c..c9806ed1dde704 100644
--- a/src/sentry/runner/commands/run.py
+++ b/src/sentry/runner/commands/run.py
@@ -699,6 +699,19 @@ def replays_recordings_consumer(**options):
     run_processor_with_signals(consumer)
 
 
+@run.command("ingest-monitors")
+@log_options()
+@click.option("--topic", default="ingest-monitors", help="Topic to get monitor check-in data from.")
+@kafka_options("ingest-monitors")
+@strict_offset_reset_option()
+@configuration
+def monitors_consumer(**options):
+    from sentry.monitors.consumers import get_monitor_check_ins_consumer
+
+    consumer = get_monitor_check_ins_consumer(**options)
+    run_processor_with_signals(consumer)
+
+
 @run.command("indexer-last-seen-updater")
 @log_options()
 @configuration