He was vicar of Linlithgow and rector of Conveth, before being provided as bishop of Brechin on 29 November 1465.
[1][2] He was allowed to retain the church of Conveth (now called Lawrencekirk) after becoming bishop, the papal documents stating that he had held this rectorship for more than nine years prior to 1465.
[1] As bishop, Balfour sat frequently in parliament, his first recorded appearance being 14 October 1467.
[3] After twenty-three years in office there was preparation to secure the appointment of William Meldrum, vicar of Brechin, to the see.
of Flemish groats was made by Walter Monypenny, prior of Loch Leven, to a Florentine merchant for securing bulls in Meldrum's favour; Meldrum was to succeed to the bishopric on the expected vacancy following "the resignation or death of the reverend father in Christ, John Balfour, now bishop of Brechin".