Corey O’Connor (D) defeated incumbent Edward Gainey (D) 54.5%-45.5% in the Democratic primary for mayor of Pittsburgh, Pennsylvania, on May 20. A Democrat has held the mayor’s office since 1934.

O’Connor and Tony Moreno (R) will now run in the general election on Nov. 4. Moreno defeated Thomas West (R) 70.6%-29.4%. 

Before the election, PennLive’s J.D. Prose wrote, “With Pittsburgh remaining a solidly blue enclave in purple Allegheny County, the party’s primary race winner will be considered the de facto next mayor although there are two GOP mayoral candidates.”

O’Connor is the controller of Allegheny County. He campaigned to build more housing and develop businesses and said, “We must create new affordable and workforce housing opportunities, and eliminate obstacles to housing construction. We must provide space for new businesses and entrepreneurs to choose Pittsburgh.” He also campaigned on public safety and said he wanted to fund centers to “provide crisis support, homelessness resources, and emergency aid, giving first responders more tools to help residents quickly and effectively.” The Allegheny County Democratic Committee and Pennsylvania’s Laborers’ Council endorsed O’Connor. The Democratic committee previously endorsed Gainey over incumbent Bill Peduto (D) in 2021.

Gainey was first elected in 2021. He ran on his record in office and his campaign website said, “Homicides are down, the state of our infrastructure has improved, affordable housing options are growing, and basic services are faster — I’m proud of my record as Mayor, and excited about what we can still achieve, together.” Gainey said he would focus on making housing more affordable, saying, “I want to build a city where everybody has an opportunity to live. To me, housing is a right. Housing is a right that everybody should have.” U.S. Rep. Summer Lee (D-Pa.) and the United Steelworkers endorsed Gainey.

Before the election, WESA’s Chris Potter discussed the national implications of the race and wrote, “What happens outside of Pittsburgh no longer stays outside of Pittsburgh.” Gainey criticized O’Connor for receiving $130,000 in donations from donors who previously supported Republican candidates. Gainey said, “There’s one place I didn’t expect to have to fend the MAGA assault, and that was the mayoral primary race… Trump’s MAGA megadonors, his consultants and corporate interests, are trying to buy the mayor’s office.” O’Connor said he received donations from “people who want to donate because they see how much Pittsburgh is struggling,” and criticized Gainey previously supporting Pittsburgh’s bid to host the Republican National Convention in Pittsburgh, saying “So, I ask, who’s progressive? Somebody who wants to stop Donald Trump or somebody who was willing to welcome Donald Trump and the Trump Republicans to Pittsburgh for their national convention?”

Gainey is the first incumbent mayor to lose in a primary election in one of the top-100 U.S. cities by population this year. In 2024, there were four incumbent mayors who lost their bids for re-election. Pittsburgh is the 67th largest city in the U.S. Click here to learn more about Pittsburgh’s 2025 elections.

Pittsburgh does not have term limits for the position of mayor. Mayors serve a four-year term. Pittsburgh is one of the 47 top 100 U.S. cities to use a strong mayor system of governance, meaning the mayor drafts budgets, sets policies, and can veto bills by the city council. To read more about the power mayors have in the top 100 cities in the country, click here.