"Sundown" is a song by Canadian folk artist Gordon Lightfoot, from the titular album, released as a single in March 1974.

"Sundown" reached No. 1 on the U.S. Billboard Hot 100 and easy listening charts^[2] and No. 13 on the Hot Country singles chart,^[3] as well as No. 1 in Canada on RPM's national singles chart. It was Lightfoot's only single to reach No. 1 on the Hot 100.

The lyrics describe a troubled romantic relationship (often cited as Cathy Smith), with the narrator recounting an affair with a "hard-loving woman [who's] got me feeling mean".

In a 2008 interview, Lightfoot said:

I think my girlfriend was out with her friends one night at a bar while I was at home writing songs. I thought, 'I wonder what she’s doing with her friends at that bar!' It's that kind of a feeling. 'Where is my true love tonight? What is my true love doing?'^[4]

Engineered by Lee Herschberg
Recorded at Eastern Sound Studios, Toronto, Ontario, Canada.

• Gordon Lightfoot: Lead and background vocals, 12-string guitar
• Red Shea: Lead electric guitar
• Terry Clements: Lead acoustic guitar
• John Stockfish: Bass
• Jim Gordon: Drums

• The musical project/collaboration of singer-songwriters Elwood covered the song in 2000. This version peaked at No. 33 on the Billboard Modern Rock Tracks chart on July 8, 2000.^[20]
• American country music singer Deryl Dodd's version of the song peaked at #59 on Billboard's Hot Country Singles & Tracks chart in 1999. It was later included on his album, Pearl Snaps (2002).
• Danish supergroup Dalton covered the song on their first album Dalton released in 1992, under the title "Selskabsmadonna".

• List of Hot 100 number-one singles of 1974 (U.S.)
• List of number-one adult contemporary singles of 1974 (U.S.)
• List of RPM number-one singles of 1974