It was Michael's seventh and final number-one single in the UK during his lifetime and is his seventh-most downloaded track there, earning a gold certification from the British Phonographic Industry (BPI) for selling and streaming over 600,000 units.

Jon Kutner from 1000 UK Number One Hits said the line "Stupid Cupid keeps on calling me and I see lovin' in his eyes" had a dual interpretation which could imply Michael's homosexuality.

[6] While reviewing Older, Stephen Thomas Erlewine from AllMusic said although "Fastlove" is the album's only dance track, it still "lacks the carefree spark of his earlier work."

He noted that Michael "deftly cruises between breathy sensuality and full-bodied belting", adding that the "icing on the cake is a chorus and refrain that are immediate sing-along fodder.

"[8] Daina Darzin from Cash Box wrote that "Fastlove" "pumps up both the volume and the velocity for a terminally danceable, happy-feet track that's sure to become a staple in discos across the U.S." She also remarked that it features "the sort of ultra-lush, opulent soul vibe that's been Michael's hallmark throughout his career.

She noted further, "It's got a silky-smooth groove with touches of brass, and Michael's voice is as stellar as ever, slick and teasing yet somehow revelatory, giving this track a hookiness despite lacking an actual chorus.

He stated, "It took real guts to release a salute to a one-night stand in this, the era of abstinence," also praising its "devilishly seductive bass" and "sleekly probing horns".

"[11] Irish Evening Herald said it is "very like" his 1992 hit "Too Funky", adding that it "restores George to his rightful place as purveyor of whiteboy R&B to a middle-class audience.

[15] A reviewer from Music & Media called it a "uncomplicated, good-time funky dance track in which the repetition of the title has a lasting effect", and noted that the production and atmosphere is "owing much to late-'70s disco grooves".

[18] Writing about the album for Rolling Stone, Al Weisel called it a "bouncy disco concoction" that is "flavored with Dr. Dre-style whistling synths.

"[21] In 2017, Dave Fawbert of ShortList called Fastlove "one of the greatest songs ever made", noting that, at a time when Britpop was at its height "George Michael decided to completely ignore it and release a truly slinky R&B/soul number which announced, with the utmost style, that he would be just as relevant in the '90s as he had been in the '80s."

He was also full of praise for Fastlove Part II, although criticized the "Summer Mix" of the song as lacking "the fruity bass of the original".

Throughout the video, various men and women who display a wide spectrum of characteristics, including one who is shy, another who is lustful, and another who is a complete emotional wreck (played by Rachel Williams), sit in the chair and use the remote control to summon more sexual characters.

[29][30] Barry Walters in a review for The Advocate, describing the performance: "During 'Fastlove' he changes the melody considerably, and a huge mass of background singers drops all sorts of gospel-influenced vocal doodads.