[1][2] Three Democrats, including Peduto, and no Republicans filed petitions to appear on the respective primary ballots before the deadline on March 7, 2017.

[4] He went on to win the general election comfortably, defeating his Republican opponent, Joshua Wander, by 73 points.

[7] In mid-February 2017, two individuals had filed to vie for the primary election endorsement of the Allegheny County Democratic Committee: Peduto and city council member Darlene Harris, the latter of whom had not officially announced a campaign.

[8][10] Harris, although losing the party endorsement, gained 40% of the committee votes and filed petitions just before the March 7 deadline to appear on the ballot in the primary, despite not having formed an official campaign.

[12] On May 16, Bill Peduto defeated John Welch and Darlene Harris to win the Democratic nomination.