A by-election was held for the New South Wales Legislative Assembly electorate of Cobar on 2 December 1911 because of the death of Donald Macdonell (Labour).[1]
Macdonell had been absent because he was unwell but he was expected to recover. His seat had been declared vacant as he was absent for an entire session. He was unopposed at the resulting by-election,[2] however he died three weeks later.[1]