A by-election was held for the New South Wales Legislative Assembly electorate of West Sydney on 15 July 1877 because Sir John Robertson was appointed Colonial Secretary, forming the fourth Robertson ministry.[1] Such ministerial by-elections were usually uncontested however on this occasion a poll was required in Central Cumberland (John Lackey and William Long), East Sydney (John Davies), Orange (Edward Combes) and West Sydney. Each minister was comfortably re-elected. Only Camden (Thomas Garrett) and Goldfields South (Ezekiel Baker) were uncontested.[2]