Samuel Osborne McCausland was a wholesale grocer, tobacco manufacturer, seed merchant and ship-owner.

McCausland was born on 25 December 1800 and in his youth served a commercial apprenticeship in London. He came to Belfast in 1825 and set up his first business premises at North Street. Following commercial development of the Victoria Street area, McCausland opened a warehouse on the street in the early 1870s and traded from the premises for over twenty-five years.

McCausland joined the Belfast Corporation in 1841 when he was elected as an alderman. He was involved in the widening and improvement of Victoria Street and in the construction of a new Town Hall at that location, which opened in 1871. He served as a member of the Belfast Harbour Commissioner for over forty years and acted as Justice of the Peace.

McCausland’s portrait was unveiled on 16 February 1882 at the Belfast Town Hall, along with the portrait of another former mayor, John Browne.