Kellow was born in Fifeshire, Scotland and educated at the University of Glasgow. He accepted the headmastership of Rockhampton Grammar School in 1912, prior to which he had published Burns and His Poetry in London publisher Harrap's 'Poetry and Life ' series. Harrap also published A Treasury of Scottish Verse, compiled by Kellow, in 1912.
The importance of Queensland Poets (1930) has been recognised because it represented the first coverage of the state's poetic contribution at an early date. Kellow was the subject of a monograph by Lorna McDonald (q.v.) published in 1981.
Kellow remained in Rockhampton until his death. Cecil Hadgraft (q.v.) was a pupil at Rockhampton Grammar School and returned there to teach.