|Westralian congressional election, 1875|
| All 100 seats in the National Assembly|
50 required for a majority
| All 50 seats in the Senate|
25 required for a majority
|5 February 1875||1880 →|
|First party||Second party|
|Party||Democratic Labour||National Unity|
|Seats won|| ▲62|
Elections were held throughout the Kingdom of Westralia on Friday, 5 February 1875 to determine the members of the 1st Royal Congress. 100 seats in the National Assembly and 50 seats in the Senate were contested during this election.
The Democratic Labour Party won the majority of seats in both houses of Congress, with 62 seats in the National Assembly, and 28 in the Senate. The National Unity Party won 28 seats in the National Assembly, and 10 in the Senate. These two parties thus became the two largest in Congress, and were therefore given the right to nominate the two Ministerial candidates, who faced each other in the ministerial elections six months later, on 5 July 1875.
Out of the candidates nominated — Harold Symons from the DLP, and Paul Arlyn, 1st Earl Arlyn from the NUP — Symons won the vote by a significant margin, and became the country's 2nd Prime Minister following the end of the term of Sir Frederick Mayweather. Symons as Prime Minister became Leader of the DLP in Congress, whilst Arlyn became Leader of the NUP in Congress.