It is a best practice to keep the SQL Agent Job owner to SA or Service Account. Please don’t make the job owner to any user’s windows ID. If the employee left the company his ID will be terminated and access will be revoked.
You can find out the jobs owner by executing the below query.
SELECT j.name, l.[name] as [JobOwner] FROM MSDB.dbo.sysjobs j INNER JOIN Master.dbo.syslogins l ON j.owner_sid = l.sid ORDER BY j.[name]
You can change the job owner by executing the below query.
EXEC MSDB.dbo.sp_update_job @job_name = 'Job Name', @owner_login_name = 'sa'