Richard Septimus Haynes KC (14 August 1857 – 20 February 1922) was an Australian barrister and politician who was a member of the Legislative Council of Western Australia from 1896 to 1902.

A political radical, he was a founder of the Eight Hours Association (advocating for the eight-hour workday), along with another future MP, John Horgan.

[1] At the 1890 general election (the first to be held for the Legislative Assembly), Haynes contested the seat of West Perth, but was defeated by Timothy Quinlan.

[2] In 1896, Haynes was elected to a six-year term in the Legislative Council, defeating a sitting member, Hugh McKernan, in Central Province.

[1] Haynes stood for parliament for a fifth time at the 1904 state election, but lost to a Labor candidate, Francis Wilson, in the seat of North Perth.