Max Engling defeated incumbent Diego Morales, Jamie Reitenour, and David Shelton to win the Republican Party nomination for Indiana Secretary of State at a June 20, 2026, convention.

Party delegates elected in the primary voted at the convention to determine which candidate would earn the right to run as the party's nominee in the state's secretary of state election on November 3, 2026. Engling won with 53% in a second round of voting after Reitenour was eliminated. Shelton received 39%, and Morales received 8%.

After Engling was the last to join the race in May 2026, U.S. Sen. Jim Banks (R) and Indiana Attorney General Todd Rokita (R) withdrew their endorsements of Morales and endorsed Engling.

WFYI's Brandon Smith wrote, "Morales has faced scrutiny for spot bonuses for employees; hiring his brother-in-law to a six-figure job; missing a legislative hearing for his agency while traveling overseas; purchasing a $90,000 vehicle for his office; and giving no-bid contracts to companies linked to campaign contributions." According to Smith, "Morales dismissed those concerns, saying they're part of him going above and beyond the call of duty in his job." Morales said, "I always enjoy these opportunities that allow me to showcase Indiana and let companies across the world know, we are open for business."

According to the Indiana Capital Chronicle's Whitney Downard ahead of the convention, "Republican hopefuls see an opportunity to challenge the embattled politician and establish themselves in contrast to the divisive officeholder."

Engling earned his bachelor's degree in political science and psychology from Indiana University Indianapolis and his master's degree in defense and strategic studies from the U.S. Naval War College. His career experience included working as central Indiana regional director and adviser to Banks. Engling ran for Indiana's 5th Congressional District in 2024, finishing third among nine candidates in the Republican primary with 10% of the vote.

Engling’s campaign website said he would “fight for Conservative election reforms, including ensuring that only citizens can vote in Indiana elections, closing primaries to prevent crossover voting, improving oversight and monitoring of business fraud, and creating greater transparency through a portal that allows citizens to report potential election issues directly.”

Shelton was elected Knox County Clerk in 2018 and also served as the Knox County Republican Party Chair at the time of the 2026 election. Shelton’s career experience included working as a private investigator and the owner of an upholstery shop. Shelton also ran for secretary of state in 2022.

Shelton's campaign website said he ran for secretary on professionalism in office, election security, preparing for the 2030 redistricting cycle, strengthening election administration, leadership, and improving the office's non-election functions. Shelton said, "I am officially in this race because Indiana deserves a Secretary of State who knows how to do the job and actually wants to do the job."

Morales won the Republican nomination at the 2022 convention over incumbent Holli Sullivan (R). He defeated Destiny Scott Wells (D) 54%-40% in the general election. Morales earned his bachelor's degree from Indiana University, master's degree in business administration from Purdue University, and an international master's degree in business administration from Tilburg University. He served in the U.S. Army and Indiana National Guard and worked in business as an executive, consultant, and entrepreneur.

Morales' campaign website listed accomplishments and future plans along four issues: protecting elections, increasing training and standards for Indiana car dealers, protecting Hoosier investments, and streamlining business services.

Reitenour earned a bachelor's degree from Southwest Missouri State University in 2001. Her career experience included working as a mortgage broker, compliance manager, ministry leader, and stay-at-home mom. Reitenour ran for governor in 2024, finishing fifth among six candidates in the Republican primary with 5% of the vote.

Reitenour's campaign website said, "Indiana does not need a world traveler serving as Secretary of State; it needs an administrative leader committed to the actual job description of the office." Reitenour supported using paper ballots instead of voting machines for Indiana elections: "No more expensive machines with third parties holding the source code in escrow. We want paper ballots with watermarks, precinct voting, and precinct-level hand counting."