First released by P.P. Arnold (UK #18 1967).
Also recorded by Cat Stevens, writer (1967).
Other hit versions by Norma Fraser (Jamaica, 1967), Keith Hampshire (CAN #1 1973), Rod Stewart (US #21/UK #1/CAN #11/AUS #19/ZIM #8 1976), Sheryl Crow (US #14/MOR #1/C&W #35/UK #37/IRE #13 2003).
From the wiki: “‘The First Cut Is the Deepest’ is a 1967 song written by Cat Stevens, originally released by P. P. Arnold in the spring of 1967. Stevens had made a demo recording of ‘The First Cut Is the Deepest’ in 1965 but had written the song only to promote his songwriting to other artists, and did not record it for commercial release until early October 1967. He sold the song for £30 to P. P. Arnold and it became a huge hit for her in the UK, reaching #18 on the UK Singles Chart.
“After several years touring the United States with the Ike & Tina Revue, P.P. Arnold emigrated to England in 1966. Impressed by her powerful and soulful voice, Mick Jagger convinced Stones manager Andrew Loog Oldham to sign Arnold to a recording contract. During this period Arnold also toured alongside Delaney and Bonnie & Friends, Small Faces, Jimi Hendrix, The Who, The Kinks, Blind Faith, David Bowie and others, and she recorded several other hits including a 1969 UK #29 hit release of ‘Angel of the Morning‘.