The singer is in the house to watch the Kansas City Chiefs take on the Tampa Bay Buccaneers ... she just arrived, wearing a mostly all-black outfit ... with a matching top, shorts and knee-high boots.

Taylor topped off her look with a Chiefs jacket ... and, she looks ready to cheer on her man as the Chiefs look to remain the only unbeaten team in the NFL.

It's the first time in four weeks Taylor's been to one of Travis' games ... but that's because the Chiefs had an off week and two road games ... remember, Taylor rarely goes to away games, and is mostly a staple at home games in KC.

Of course, Taylor was touring too ... but she's got a little bit of a break before taking her "Eras" tour up to Canada ... and, she's taking advantage of the downtime to support Travis.

It's likely Taylor will watch from her perch in a suite ... and it will be interesting to see how many times she's shown on the MNF broadcast.

For his part, Travis showed up to work with a canned beverage in one hand and his Jordan football cleats in the other ... wearing a brown jacket and pants and some Air Jordan IXs.