Written and first recorded by Ian & Sylvia (1964).
Also recorded by The Chad Mitchell Trio (1965), The Vogues (1965).
Hit versions by We Five (US #3 1965), Crispian St. Peters (US #36/UK #2 1966), Barry McGuire (ITA #19 1966).
From the wiki: “‘You Were On My Mind’ was written by Sylvia Tyson in 1964, and originally performed and recorded by her and Ian Tyson as the duo Ian & Sylvia. It first appeared on their 1964 album, Northern Journey. The following year, We Five recorded a cover that charted in the Billboard Top 5. Crispian St. Peters (‘The Pied Piper’) scored a sizable UK hit in 1966 with his cover version. A 1966 cover by Barry McGuire (‘Eve of Destruction’, ‘California Dreamin’‘) peaked in the Italian Top 20.”