diff --git a/moto/events/models.py b/moto/events/models.py
--- a/moto/events/models.py
+++ b/moto/events/models.py
@@ -966,6 +966,24 @@ def parse(self) -> Dict[str, Any]:
             raise InvalidEventPatternException(reason="Invalid JSON")
 
 
+class PartnerEventSource(BaseModel):
+    def __init__(self, region: str, name: str):
+        self.name = name
+        self.arn = f"arn:aws:events:{region}::event-source/aws.partner/{name}"
+        self.created_on = unix_time()
+        self.accounts: List[str] = []
+        self.state = "ACTIVE"
+
+    def to_dict(self) -> Dict[str, Any]:
+        return {
+            "Arn": self.arn,
+            "CreatedBy": self.name.split("/")[0],
+            "CreatedOn": self.created_on,
+            "Name": self.name,
+            "State": self.state,
+        }
+
+
 class EventsBackend(BaseBackend):
     """
     Some Moto services are configured to generate events and send them to EventBridge. See the AWS documentation here:
@@ -991,7 +1009,7 @@ def __init__(self, region_name: str, account_id: str):
         super().__init__(region_name, account_id)
         self.next_tokens: Dict[str, int] = {}
         self.event_buses: Dict[str, EventBus] = {}
-        self.event_sources: Dict[str, str] = {}
+        self.event_sources: Dict[str, PartnerEventSource] = {}
         self.archives: Dict[str, Archive] = {}
         self.replays: Dict[str, Replay] = {}
         self.tagger = TaggingService()
@@ -999,6 +1017,8 @@ def __init__(self, region_name: str, account_id: str):
         self._add_default_event_bus()
         self.connections: Dict[str, Connection] = {}
         self.destinations: Dict[str, Destination] = {}
+        self.partner_event_sources: Dict[str, PartnerEventSource] = {}
+        self.approved_parent_event_bus_names: List[str] = []
 
     @staticmethod
     def default_vpc_endpoint_service(
@@ -1041,7 +1061,7 @@ def _process_token_and_limits(
         return start_index, end_index, new_next_token
 
     def _get_event_bus(self, name: str) -> EventBus:
-        event_bus_name = name.split("/")[-1]
+        event_bus_name = name.split(f"{self.account_id}:event-bus/")[-1]
 
         event_bus = self.event_buses.get(event_bus_name)
         if not event_bus:
@@ -1901,5 +1921,36 @@ def delete_api_destination(self, name: str) -> None:
                 f"An api-destination '{name}' does not exist."
             )
 
+    def create_partner_event_source(self, name: str, account_id: str) -> None:
+        # https://docs.aws.amazon.com/eventbridge/latest/onboarding/amazon_eventbridge_partner_onboarding_guide.html
+        if name not in self.partner_event_sources:
+            self.partner_event_sources[name] = PartnerEventSource(
+                region=self.region_name, name=name
+            )
+        self.partner_event_sources[name].accounts.append(account_id)
+        client_backend = events_backends[account_id][self.region_name]
+        client_backend.event_sources[name] = self.partner_event_sources[name]
+
+    def describe_event_source(self, name: str) -> PartnerEventSource:
+        return self.event_sources[name]
+
+    def describe_partner_event_source(self, name: str) -> PartnerEventSource:
+        return self.partner_event_sources[name]
+
+    def delete_partner_event_source(self, name: str, account_id: str) -> None:
+        client_backend = events_backends[account_id][self.region_name]
+        client_backend.event_sources[name].state = "DELETED"
+
+    def put_partner_events(self, entries: List[Dict[str, Any]]) -> None:
+        """
+        Validation of the entries is not yet implemented.
+        """
+        # This implementation is very basic currently, just to verify the behaviour
+        # In the future we could create a batch of events, grouped by source, and send them all at once
+        for entry in entries:
+            source = entry["Source"]
+            for account_id in self.partner_event_sources[source].accounts:
+                events_backends[account_id][self.region_name].put_events([entry])
+
 
 events_backends = BackendDict(EventsBackend, "events")
diff --git a/moto/events/responses.py b/moto/events/responses.py
--- a/moto/events/responses.py
+++ b/moto/events/responses.py
@@ -512,3 +512,33 @@ def delete_api_destination(self) -> Tuple[str, Dict[str, Any]]:
         name = self._get_param("Name")
         self.events_backend.delete_api_destination(name)
         return self._create_response({})
+
+    def create_partner_event_source(self) -> str:
+        name = self._get_param("Name")
+        account_id = self._get_param("Account")
+        self.events_backend.create_partner_event_source(
+            name=name,
+            account_id=account_id,
+        )
+        return "{}"
+
+    def describe_event_source(self) -> str:
+        name = self._get_param("Name")
+        event_source = self.events_backend.describe_event_source(name)
+        return json.dumps(event_source.to_dict())
+
+    def describe_partner_event_source(self) -> str:
+        name = self._get_param("Name")
+        event_source = self.events_backend.describe_partner_event_source(name)
+        return json.dumps({"Arn": event_source.arn, "Name": event_source.name})
+
+    def delete_partner_event_source(self) -> str:
+        name = self._get_param("Name")
+        account_id = self._get_param("Account")
+        self.events_backend.delete_partner_event_source(name, account_id)
+        return "{}"
+
+    def put_partner_events(self) -> str:
+        entries = self._get_param("Entries")
+        self.events_backend.put_partner_events(entries)
+        return json.dumps({"Entries": [], "FailedEntryCount": 0})

Thanks for opening; setting this as a feature request.
please , I am looking for this feature too.
Do you have a plan for this implement ? Thanks!
would be great to have this!
diff --git a/tests/test_events/test_events_partners_integration.py b/tests/test_events/test_events_partners_integration.py
new file mode 100644
--- /dev/null
+++ b/tests/test_events/test_events_partners_integration.py
@@ -0,0 +1,105 @@
+import boto3
+import json
+import os
+
+from datetime import datetime
+from moto import mock_events, mock_logs, settings
+from unittest import mock, SkipTest
+
+
+@mock_events
+def test_create_partner_event_bus():
+    client_account = "111122223333"
+    client = boto3.client("events", "us-east-1")
+    client.create_partner_event_source(
+        Name="mypartner/actions/action1", Account=client_account
+    )
+    resp = client.describe_partner_event_source(Name="mypartner/actions/action1")
+    assert (
+        resp["Arn"]
+        == "arn:aws:events:us-east-1::event-source/aws.partner/mypartner/actions/action1"
+    )
+    assert resp["Name"] == "mypartner/actions/action1"
+
+
+@mock_events
+def test_describe_partner_event_busses():
+    if settings.TEST_SERVER_MODE:
+        raise SkipTest("Can't change accounts easily in ServerMode")
+    # Having a separate partner account isn't 'strictly necessary - we could do that from the main account
+    # But it makes it more obvious for the reader that we're accessing different accounts IMO
+    partner_account = "111122223333"
+    client_account = "444455556666"
+    client = boto3.client("events", "us-east-1")
+    name = "mypartner/actions/action1"
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": partner_account}):
+        client.create_partner_event_source(Name=name, Account=client_account)
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": client_account}):
+        resp = client.describe_event_source(Name=name)
+        assert resp["Name"] == name
+        assert resp["CreatedBy"] == "mypartner"
+        assert resp["State"] == "ACTIVE"
+
+        client.create_event_bus(Name=name, EventSourceName=name)
+        resp = client.describe_event_bus(Name=name)
+        assert resp["Name"] == name
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": partner_account}):
+        client.delete_partner_event_source(Name=name, Account=client_account)
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": client_account}):
+        resp = client.describe_event_source(Name=name)
+        assert resp["State"] == "DELETED"
+
+
+@mock_events
+@mock_logs
+def test_put_partner_events():
+    if settings.TEST_SERVER_MODE:
+        raise SkipTest("Can't change accounts easily in ServerMode")
+
+    partner_account = "111122223333"
+    client_account = "444455556666"
+    events = boto3.client("events", "us-east-1")
+    logs = boto3.client("logs", region_name="us-east-1")
+    name = "mypartner/actions/action1"
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": partner_account}):
+        events.create_partner_event_source(Name=name, Account=client_account)
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": client_account}):
+        events.create_event_bus(Name=name, EventSourceName=name)
+
+        log_group_name = "/test-group"
+        rule_name = "test-rule"
+        logs.create_log_group(logGroupName=log_group_name)
+        log_group_arn = (
+            f"arn:aws:logs:us-east-1:{client_account}:log-group:{log_group_name}"
+        )
+        events.put_rule(
+            Name=rule_name,
+            EventPattern=json.dumps({"account": [client_account]}),
+            State="ENABLED",
+        )
+        events.put_targets(
+            Rule=rule_name,
+            Targets=[{"Id": "logs", "Arn": log_group_arn}],
+        )
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": partner_account}):
+        resp = events.put_partner_events(
+            Entries=[
+                {
+                    "Time": datetime.now(),
+                    "Source": name,
+                    "DetailType": "test-detail-type",
+                    "Detail": json.dumps({"foo": "123", "bar": "123"}),
+                }
+            ]
+        )
+        assert resp["FailedEntryCount"] == 0
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": client_account}):
+        log_events = logs.filter_log_events(logGroupName=log_group_name)["events"]
+        assert len(log_events) == 1
+        assert "test-detail-type" in log_events[0]["message"]

Add support for EventBridge partner methods
Thanks so much for the great work on initial support in #2322. Specifically I am looking for support for the following partner methods.

* `create_partner_event_source()`
* `delete_partner_event_source()`
* `put_partner_events()`


tests/test_events/test_events_partners_integration.py::test_describe_partner_event_busses tests/test_events/test_events_partners_integration.py::test_create_partner_event_bus tests/test_events/test_events_partners_integration.py::test_put_partner_events