The 2017 season was the Kansas City Chiefs' 48th in the National Football League (NFL), their 55th as the Kansas City Chiefs, their 58th overall, their fifth under head coach Andy Reid and their first under general manager Brett Veach.

They won the AFC West, but lost to the Tennessee Titans in the wild card round after blowing a 21–3 lead at the half.

The season was the first to feature future two-time MVP and three-time Super Bowl MVP Patrick Mahomes whose first start came in the last game of the regular season against the Denver Broncos, a game which had no playoff implications as the Chiefs had secured the division in Week 16.

[1] On July 10, the Chiefs promoted co-director of player personnel Brett Veach to general manager.

[3] The Chiefs most notable transaction of the off-season came when they released the franchise's all-time leading rusher, Jamaal Charles, after 9 seasons.

In the game, the Chiefs had a commanding 21–3 lead at halftime, but failed to score a single point in the second half.

Additionally by beating the Patriots in Week 1, the Chiefs extending their winning streak against the defending Super Bowl champs to six.

The Raiders scored the game-winning touchdown after multiple holding penalties on Kansas City forced several untimed downs after time expired.

The Chiefs had a strong first half, building a 21–3 halftime lead and sending the home crowd into a frenzy.

However, the Titans were able to catch fire, with a batted down touchdown pass from Marcus Mariota to himself, to make the score 21–10.

The Chiefs were not able to recover after this touchdown, and the Titans outscored Kansas City 19–0 in the second half to win 22–21.

With the loss, the Chiefs ended their season at 10–7 and lost 6 straight home playoff games, the worst in NFL history.