John Fetterman, the Democratic nominee for one of the country’s most important U.S. Senate seats, will hold a campaign rally in Erie next week, his first official event since suffering a stroke in May. Democrats have been awaiting Mr. Fetterman’s return to the trail, where he’ll aim to convince voters that they should choose him over Republican Mehmet Oz in November.

Mr. Fetterman will hold the rally on Aug. 12 in Erie, “one of Pennsylvania’s biggest bellwether counties,” his campaign noted. As politicians from both parties have routinely quipped for years, as goes Erie, so goes Pennsylvania.

“I’ve visited Erie dozens and dozens of times in the past, and I am honored and proud to be returning to the campaign trail here,” Mr. Fetterman said in a statement.

Mr. Fetterman, Pennsylvania’s lieutenant governor, suffered a stroke days before the May primary, when he emerged from a field that included U.S. Rep. Conor Lamb and state Rep. Malcolm Kenyatta to become the party’s torchbearer.