 In 1920 Whyte was appointed Bishop of Dunedin and on the 12th day of December in that year he was consecrated by Archbishop Redwood in St. Joseph's Cathedral, Dunedin with James Liston who had been appointed Coadjutor Bishop of Auckland.During Whyte's episcopate the number of priests in the diocese doubled from 40 to 81; there was a similar increase in the children attending Catholic schools, from 3060 to 6120.In 1927 he founded St. Kevin's College, Oamaru.