Rock singer. Connolly was born in Hamilton, adopted into the McManus family at birth and thus half-brother to actor Mark McManus (1935-94). At 18, discovering he was adopted he changed his surname back to that of his mother. He moved to Middlesex (England) and began his rock career.
With Mick Tucker, Connolly formed the band Sweetshop, later shortened to Sweet, which came to lead the 'glam rock' genre. After various changes in the line-up, recording companies and record flops, the band signed on with RCA. They had hits with the singles including Funny Funny, Co Co (1971), Fox on the Run, Action (1974) and Love is like Oxygen (1978). Their albums include Gimmee Dat Ding (1971), Funny How Sweet Co Co Can Be (1971), Sweet Fanny Adams (1974), Desolation Boulevard (1974) and Level Headed (1978).
As the band developed their sound towards 'heavy metal', Connolly became increasingly unhappy and left in 1979 to pursue a relatively unsuccessful solo career. Connolly had developed a severe drinking problem which damaged his health. He survived a number of heart-attacks and continued in the music business until his death, even discussing a 30th anniversary reunion of Sweet. However, he succumbed to kidney failure in Slough (Berkshire, England).