Alexander William Roberts FRSE FRAS FRSSA (4 December 1857 – 21 January 1938) was a Scottish-born, South African teacher and an amateur astronomer.

His father, William Henry Roberts, moved to Admiralty House, on Newhaven Road in Leith, north of Edinburgh in his youth.

[1] Alexander was educated at St James Free Church School in Leith.

[3] As a youth he developed an interest in astronomy, but, after applying for a post at the Edinburgh Observatory, was dissuaded from a career by Charles Piazzi Smyth, the Astronomer Royal for Scotland.

He continued his observations for over 30 years, and pioneered the study of close binary systems.

Much of his work was communicated through Edward C. Pickering, the director of the Harvard College Observatory.

Seen as an able and unbiased mediator he also chaired the commission into the 1920 riots at Port Elizabeth and the 1922 Bondelswarts Rebellion.