Chad Bowar of
Ultimate Metallica praised the song's "punch and attitude", while Melinda Newman of
Billboard described "Ain't My Bitch" as "hard and crunchy". Drew Millard of
Pitchfork called the song "comically distasteful" and mocked Hetfield for "taking great pains to never pronounce it the same way twice. In the first chorus it's 'biiiiii-tchah," while in the second chorus "he goes 'betch-yah.'"
Loudwire placed the song at No. 46 on their ranking of every Metallica song and opined it "sounded like
Lynyrd Skynyrd on steroids", adding that "had they released this as the first
Load single, the media narrative around the band's post-
Black Album return might have been a lot different." On another
Loudwire list, "Ranking the Opening Song on Every Metallica Album", the song was ranked at No. 10, with Phillip Trapp labeling it "marginally better than 'That Was Just Your Life' as an album opener" and that it "gives
Load its gritty first song to show Metallica can still rock". ==Live performances==