"Ex for a Reason" is a song by American singer Summer Walker with rapper JT of hip hop duo City Girls, released on October 15, 2021, as the lead single from Walker's second studio album, Still Over It (2021).

"Ex for a Reason" is an uptempo pop-rap song that conveys "emotions behind dating someone that’s moved on from a past relationship".

[4][5] Andy Kellman of AllMusic described the song as "a Miami-meets-Atlanta bass jam and one of the era's most flavorsome crossover R&B hits.

[7] The official music video, directed by Lacy Duke, was released on October 19, 2021.

[8] The video begins with Summer and her friends sitting at a local gas station and then riding through Atlanta, Georgia in an Oldsmobile 442 convertible with "Forever Atlanta" on the license plate,[8] before later arriving to a house party.