On May 27, 2022, Rivas announced he had votes to become the next Speaker of the California State Assembly, challenging incumbent speaker Anthony Rendon. Rendon challenged Rivas's claim, with the two meeting to talk about the challenge, later releasing a joint statement that Rendon would be the leader at last until the end of the legislative session. On November 10, 2022, the Assembly voted to make Rivas the next Speaker in 2023, alongside re-electing current speaker Rendon for the 2022–23 year. He will assume office on June 30, 2023.
