Elections were held in the state of Western Australia on 8 April 1933 to elect all 50 members to the Legislative Assembly. The one-term Nationalist-Country coalition government, led by Premier Sir James Mitchell, was defeated by the Labor Party, led by Opposition Leader Philip Collier.

The National Party of Australia (WA) Inc, branded The Nationals WA, is a political party in Western Australia. It is affiliated with the National Party of Australia, but maintains a separate structure and identity. Since the 2021 state election, the Nationals WA is the senior party in an opposition alliance with the WA Liberal Party in the WA Parliament. Prior to the election, the National Party was sitting in the crossbench, and the Liberal Party was the sole opposition party. The election resulted in the National Party winning more seats than the Liberal Party, and gaining official opposition status. Under the opposition alliance, the National Party leader and deputy leader would be the opposition leader and deputy opposition leader, respectively, the first since 1947, and each party would maintain their independence from each other.