Pop superstar supports rumored boyfriend at Chiefs game in Kansas City. Swift wore a red Chiefs sweater and a bracelet with Kelce's number 87 for the game.
Swift sat and danced with Brittany Mahomes, wife of Chiefs quarterback Patrick Mahomes, in the first quarter.
CBS Sports reporter Tracy Wolfson hinted at Swift's appearance in a post on Sunday.
Swift attended her fourth Chiefs game with Kelce, whom she was first seen with during a game against the Bears.
Swift made the Chiefs' Oct. 1 game against the Jets a star-studded event with her entourage.
Ryan Reynolds, Lively's husband, joined Hugh Jackman, his co-star from "Deadpool 3" and fellow Marvel actor, at the event.
Swift attended Chiefs vs. Broncos game on Oct. 12. The singer wore a black dress and red varsity jacket.
Swift celebrated with another athlete's guest during the game. Swift and Mahomes' wife cheered together during the game.