"I Feel Fine" is a riff-driven rock song written primarily by John Lennon (credited to Lennon/McCartney) and released in 1964 by The Beatles as the A-side of their eighth British single. The single reached the top of the UK charts on 12 December of that year, displacing The Rolling Stones' "Little Red Rooster," and remained there for five weeks. It also reached the top of the Billboard Hot 100 in late 1964. The B-side was "She's a Woman".
"I Feel Fine" was the first of six number one songs in a row on the American charts, a record at the time. The subsequent singles were "Eight Days a Week", "Ticket to Ride", "Help!", "Yesterday", and "We Can Work It Out". The record was equaled by The Bee Gees in 1979 and surpassed by Whitney Houston in 1988.
It was also the first Beatles single to be released almost concurrently in the US and the UK.
Lennon wrote the guitar riff while in the studio recording "Eight Days a Week" ] "I wrote 'I Feel Fine' around that riff going on in the background," he recalled. "I told them I'd write a song specially for the riff. So they said, 'Yes. You go away and do that,' knowing that we'd almost finished the album Beatles for Sale. Anyway, going into the studio one morning, I said to Ringo, 'I've written this song but it's lousy.' But we tried it, complete with riff, and it sounded like an A side, so we decided to release it just like that." George Harrison said that Lennon's riff was influenced by a riff in "Watch Your Step", a 1961 release written and performed by Bobby Parker and covered by the Beatles in concerts during 1961 and 1962.
Paul McCartney said the drums on "I Feel Fine" were inspired by Ray Charles's "What'd I Say".