"Build Me Up Buttercup" is a song written by Mike d'Abo and Tony Macaulay, and released by the Foundations in 1968 with Colin Young singing lead vocals. Young had replaced Clem Curtis during 1968, and this was the first Foundations hit on which he sang.

It hit No. 1 on the Cash Box Top 100 and No. 3 on the US Billboard Hot 100 in early 1969. It was also a No. 2 hit in the United Kingdom, for two non-consecutive weeks, behind "Lily the Pink" by the Scaffold. It was quickly certified gold by the RIAA for sales of over a million US copies.