"Old Siam, Sir" is a hard rock single from Wings' 1979 album, Back to the Egg.

[1] The B-side, "Spin It On" in the UK was also a track from the album, "Back to the Egg".

"Old Siam, Sir" was also the B-side of the US single "Arrow Through Me".

Wings drummer Steve Holley, while playing keyboards during a studio session, developed a chord sequence that was eventually used in the instrumental section of the song.

[2] Paul McCartney and guitarist Denny Laine later recorded an instrumental demo for the song called "Super Big Heatwave".