Big congrats to Brittany Mahomes -- she’s just welcomed her third little bundle of joy with hubby Patrick Mahomes!

Brittany shared the exciting news on IG minutes ago ... revealing the couple's new little girl will be called Golden Raye Mahomes. Brittany added that the newborn came sometime on Sunday.

The pair first revealed Baby No. 3 was on the way back in July, with Brittany later confessing this pregnancy was the toughest one yet -- she's been dealing with exhaustion, sickness and skin issues.

The happy couple already has its hands full with 3-year-old daughter Sterling, and 2-year-old son Bronze -- and the parents have said this newborn will be their final family addition.

Golden won't have to wait long to see Dad on the football field ... he's back in action on Sunday, when the Chiefs take on the Texans in a playoff game.

Congrats, y'all!