Robert Officer Blackwood (24 June 1861 – 22 September 1940) was an Australian politician, businessman and pastoralist.

On petition by the former member, John Chanter, however, the result was declared void on the grounds of electoral irregularities.

Blackwood continued to be active in rural affairs, becoming vice-president of the Pastoralists' Union of Southern Riverina in 1906.

Blackwood married Constance Ferrier Mailton on 23 July 1895 at St Paul's Cathedral, Melbourne.

Despite his deteriorating health he maintained contact with his business affairs until his death on 22 September 1940 at St Kilda; he was survived by his wife.