Written by Glenn Frey and Don Henley, this song was inspired by the soul music Frey was listening to when he started writing it on the piano. Artists like B.B. King and Al Green were a big influence on many songs on the album.
In a 1975 interview with Phonograph Record, Frey explained: "It's like, puttin' things off... Everybody I'm sure has said, 'One of these nights I'm gonna...' Gonna drive back to that restaurant an' take that waitress in my arms, whatever. Find that girl, make that money, buy that house. Move to that country. Any of that stuff. Everyone's got his ultimate dream, savin' it for 'someday.' And 'someday' is up to you."
Don Felder, who was the Eagles newest guitarist, came up with the opening bass line. In a 1975 Rolling Stone interview, Don Henley credited Felder with helping the Eagles get away from ballads: "With Don Felder, we can really rock. He's made us nastier and he's done a great guitar solo on One Of These Nights."
In the same Rolling Stone article, Don Henley said that this song was challenging to sing live: "My voice has to be just right to hit the high notes. Sometimes I make it, sometimes I don't."
Glenn Frey cited this as an example of how he and Don Henley clicked as songwriters. "I'd go over to the piano and say, 'Hey, what do you think of this?' he told Tavis Smiley. "I'd play something, and he'd go, 'Yeah, I like that, I like that.' Maybe just get up and start singing. That's the way we wrote 'One of These Nights.' I just went over to the piano and I started playing this little minor descending progression, and he comes over and goes, (singing) 'One of these nights.' I go, yeah, yeah."
This was the Eagles second #1 single in America, preceded by "Best Of My Love" a year before.
The album One Of These Nights sold platinum in the UK and Canada, and sold 4x platinum in the US. It was the Eagles highest-selling album to date, but their next album Hotel California sold even better.
A word about that platinum rating: In 1976, album sales were growing at such a fast clip that the RIAA introduced the platinum ranking for the first time. Guess which album was the one to receive the first platinum status? Greatest Hits 1971-1975 by The Eagles.
According to Frank Moriarty's Seventies Rock - The Decade of Creative Chaos, The Eagles' chief influence was The Byrds. Eagles' vocalist and guitarist Bernie Leadon was a former member of the Flying Burrito Brothers, a group which gets two of its members (Gram Parsons and Chris Hillman) from The Byrds.
Another significant development in Eagles history happened around the time of this album. Bill Szymczyk (a man whose surname spelling must surely vex the devil himself) had become the Eagles' new producer, joining them from The James Gang - One Of These Nights was their first full album together. Their former producer, Glyn Johns, had left the scene due to artistic differences during On The Border - Johns wanted to maintain a country sound, but the band wanted to break out more into the mainstream rock sound.