December 1870 West Sydney colonial by-election

A by-election was held for the New South Wales Legislative Assembly electorate of West Sydney on 30 December 1870 because John Robertson was appointed Colonial Secretary and William Windeyer was appointed Solicitor General in the third Martin ministry. Such ministerial by-elections were usually uncontested and the other ministers were all re-elected unopposed.

Result
John Robertson was appointed Colonial Secretary and William Windeyer was appointed Solicitor General in the third Martin ministry.