William Frederick Foster (29 August 1865 – 21 July 1936) was an Australian building contractor, businessman, politician and member of the New South Wales Legislative Assembly.

Foster started life as a carpenter in 1882, and he held various jobs with building-related companies, eventually becoming a partner in a successful construction business with his father and brother in 1883.

[3] Foster strongly opposed Michael Bruxner's Transport Act of 1930, which regulated private bus services in order to protect the failing government-owned tramways and railways.

[11] He said the policy was unfair to bus drivers and conductors in the city, whose "only crime was that they were giving service to the public and earning an honest living".

[12] He called attention to the growing congestion on the government-owned tramways and noted that Sydney's public transportation system was failing to cope despite costing millions of pounds.

He said that taxis had completely revolutionised transport in Paris, and that successful transit services in London were being provided to the city by private enterprise.

However, although he was a loyal supporter of the Coalition's Stevens-Bruxner government, he frequently displayed an independence of spirit and often engaged in vigorous debate with members of his own political party.

"[11] After his death, politician Eric Spooner said that Foster exercised an independence in Parliament which commanded the respect of every member of the Legislative Assembly.

Amid the growth in popularity of flats in the 1920s, some Sydney councils proposed bans or restrictions on their development, arguing that the new multi-story buildings were obstructing views from existing neighbouring homes.

Foster objected to a total prohibition, instead suggesting that the Institute of Architects and Master Builders' Association should each nominate a technical representative to advise councils, in an honorary capacity, on flat design.

[1] Ada was interested in charity and social reform, and was associated with the appeal for funding of the Eastern Suburbs Hospital in Queens Park, of which William Foster was later elected chairman.

In the midst of concluding a declamatory speech he suddenly stopped, lost the thread of his argument, became incoherent, collapsed on to his table, and died moments later.

The manager of a private taxi business offered dozens of taxi-cabs free of charge for his funeral procession as a mark of respect for Foster being "always prepared to take up with the government any just and reasonable claim put forward".