Callan was born in Dublin, Ireland to John Bartholomew Callan and his wife Isabella (née Duthie) and educated at Jesuit's College, Dublin.

[1] Following the resignation of Robert Lyons, he entered state politics in 1889,[1] winning a by-election for the seat of Fitzroy.

[2] Callan held the seat until the 1902 state election[1] which he did not contest.

[3] Callan was then appointed to the Queensland Legislative Council in July 1902, remaining a member till his death ten years later.

He was a director of Walter Reid & Co., Mt Morgan Gold Mining Co., and the National Bank.