It was released and serviced to contemporary hit radio on September 27, 2016, through Epic Records and Syco Music as the third and final single from the group's second studio album, 7/27 (2016) as the opening track.

[3] "That's My Girl" is mainly an R&B anthemic track with elements of electro-pop and lyrical themes focused on female empowerment, encouragement and feminist influences.

The dystopian clip follows the group around an apocalyptic setting where they perform choreographed dance routines and save people trapped around a village dressed in white-colored outfits, inspired by the film Mad Max.

[15] The song opens with Brooke singing the first verse: "Who's been working so damn hard?/ You got that head on overload," before praising "that flawless body", accompanied by horn samples.

"[14][18] Adam R. Holz from website Plugged In Online, described "That's My Girl" as an "empowerment anthem that emphasizes the importance of women working hard, taking charge of their lives and not letting manipulative men define them.

Writing for the Los Angeles Times, Gerrick D. Kennedy called the song a "horn driven bombast" and states that it "delivers a punchy message of female unity".

[19] While reviewing the album 7/27, Christopher R. Weingarten from Rolling Stone wrote that the track did not compare to "Boss", the group's first single from Reflection but concludes saying ""That's My Girl" bites its honking horns just fine and delivers a booming addendum to its empowering message".

[20] Digital Spy's Lewis Corner wrote, "'That's My Girl' is basically the bolder, more fierce cousin of 'Worth It' with its strutting brass and a chorus powerful enough to launch a NASA mission.

"[21] Mike Neid from Idolator included the song in his "should have been bigger" category, praising the "harmonious and explosive cut" the group executed and its slick production.

[22] In a mixed review, Michael Smith of Renowned for Sound criticized the song's production, commenting on how the transitions to different verses can "feel disjointed in a few ways".

[23] Conversely, Lucas Villa of AXS raved about the song, calling it "one of the best girl power anthems in pop music as of late" and said the group "slay accordingly with this brassy and sassy number.

"[24] Sharing similar sentiments, Mike Wass from Idolator called the track a "sassy smash" saying it was "another fiery female empowerment anthem built around a killer horn sample.

Following the group's performance at the 2016 American Music Awards on November 20, 2016, the song debuted on the Billboard Hot 100 at number 73[28] for the week marked December 10, 2016.

Injured townsfolk are seen as the group then starts singing in solo shots in an all-black ensemble in front of a lit rock wall.

"[41] Entertainment Weekly's Nolan Feeney wrote that "the quintent played sexy emergency workers in a Hunger Games-esque dystopian society that's been rocked by catastrophe.

[43] In an analysis by Vulture, Halle Keifer expressed a confused perspective on the video, asking "do people really want to see Fifth Harmony literally dancing in the rubble of a war-ravaged city?"

[44] Carl Williott from Idolator felt that the video was "a spiritual sequel" to the group's "similarly utilitarian "Work from Home" (2016) construction site visual.

[22] Kelly Lawler of USA Today noted the video's nods to popular dystopian films including The Maze Runner and The Hunger Games.

The X Factor series 13 contestant Gifty Louise performed a cover of the song during the live week one, which received the favour and praise of all four judges.