A Certain Ratio (abbreviated as ACR) are an English post-punk band formed in 1977 in Flixton, Greater Manchester by Peter Terrell (guitar, electronics) and Simon Topping (vocals, trumpet), with additional members Jez Kerr (bass, vocals), Martin Moscrop (trumpet, guitar), Donald Johnson (drums), and Martha Tilson (vocals) joining soon after.
Drawing heavy influence from funk as well as disco and Latin percussion, the band were among to first to debut on Tony Wilson's Factory Records in 1979 with "All Night Party," produced by Martin Hannett. During ACR's early years with Factory, they scored seven Top Ten U.K. independent releases, highlighted by "Flight" and "Waterline," and released five albums beginning with The Graveyard and the Ballroom (1979).
Following late-'80s and early-'90s phases with major-label A&M and Rob Gretton's independent Robs Records, ACR were intermittently active. They returned to the studio for the 2008 album Mind Made Up and since then have continued to perform, with their catalog recirculated through an arrangement with Mute Records. ACR continued to perform into the late 2010s, and during 2017-2019 expanded, reissued, and anthologized their catalog once more, this time through Mute Records, through whom they continue to release new recordings.