His clubs included Sunderland, and also and was part of their European Cup victory in 1980, coming on as a substitute in the final. His career took shape under the guidance of Derby manager Brian Clough after moving from Sunderland for £20,000 in 1967. There was initial criticism of him as he was seen as a large but slow forward.
O'Hare followed Clough to Leeds United in 1974, however the latter left Leeds after only 44 days in the job. O'Hare was reunited with Clough after a transfer to in February 1975. He and John McGovern were signed for a combined £130,000.
Between 1977 - 1978 John played football in the North American Soccer League for Dallas Tornado, he made 40 appearances and scored 14 goals. John is currently a part-time chauffeur for Toyota and is a host of the executive/VIP guest suite at 's home games.