The deadline to register to vote in Arizona’s primary election is Monday, June 22. All registered voters can cast a ballot for the primary election. As voters prepare for this election season, here are some answers to frequently asked questions about Arizona’s primary election. A: July 21, 2026 June 22 is the voter registration deadline. June 24 early in-person voting begins. July 10 is the last day to request a ballot by mail. July 14 mail-in ballots should be sent back.