Co-written and originally recorded by Brenda Holloway (US #39/R&B #40 1967).
Other hit version by Blood, Sweat & Tears (US #2/MOR #18/R&B #46/CAN #1/UK #35/AUS #14 1969).
From the wiki: “By 1967, Brenda Holloway had been recording for Motown Records since 1964 and had struggled with Berry Gordy over control of her music, alleging that Gordy had forced her to sing Mary Wells’ ‘leftover tracks’ after the Motown singer left the label in 1964. Along with her sister Patrice, using music provided by Frank Wilson and with additional help from Gordy himself, Holloway co-wrote ‘You’ve Made Me So Very Happy.’ Coincidentally, Holloway recorded the song after a breakup with a boyfriend.
“Shortly after the release of the song, Holloway left Motown and the song was eventually featured on the ‘second’ Holloway album, The Artistry of Brenda Holloway. After two more years singing background for acts like Joe Cocker, Holloway retired to marry a preacher and have a family. Holloway would eventually return to music full time by the mid-1990s.
“Holloway’s song got a big boost when the jazz-rock group Blood, Sweat & Tears covered it in 1969. The song became one of the group’s biggest hits, reaching #2 on the Billboard Hot 100 in the United States in April 1969.”
Blood, Sweat & Tears, “You’ve Made Me So Very Happy” (1969):