"So Hard" is a song by English synth-pop duo Pet Shop Boys, released in September 1990 as the lead single from their fourth studio album, Behaviour (1990).

"[6] Larry Flick from Billboard felt that "So Hard" "maintains the fun and frothy disco melodrama of past efforts, while striking enough of a modern pop stance to encourage alternative and top 40 radio airplay.

"[3] James Muretich from Calgary Herald said the song, "about a couple faithfully unfaithful to each other", "reflect a detached sadness set against a dreamy synthesizer background that barely sashays across the dancefloor.

"[8] Paul Lester from Melody Maker named it Single of the Week, writing, "Notwithstanding the radar signals, laser beams and acidic bleeps which squiggle at the start, "So Hard" is immediately, unmistakably Pet Shop Boys.

"[10] Nick Robinson from Music Week said, "A welcome return, this time with Harold 'Axel F' Faltermeyer co-producing, and a typical semi-orchestral pop song with those familiar heavy dance beats and another catchy chorus.

"[4] Roger Morton from NME wrote that "So Hard" is "familiar Pet Shoppies territory", with its "superior hit factory pulse, boys town keyboard slashes and darkly tainted love-lyric.