Umar joined Real Sociedad on transfer deadline day from Almeria as a replacement to Alexander Isak who headed to Newcastle United.
Alvaro Morata opened the scoring for Atletico Madrid in the fifth minute
Sadiq Umar replaced Alexander Sorloth early in the second half to make his debut for Real Sociedad.
He restored parity for the hosts a few minutes later with a header from Mohamed Ali-Cho's cross.
He almost doubled Real Sociedad's lead, but his effort was saved by Atletico goalkeeper Jan Oblak.
Both sides held to share the spoils, a point was enough to move Real Sociedad to the 8th position on the log, while Atletico Madrid are on the sixth position with 7 points.
Sadiq Umar has now scored three Laliga goals in the 2022/23 season, he scored two for his former club, Almeria, before joining Real Sociedad.