Democratic U.S. Rep. Andy Kim was elected Tuesday to the U.S. Senate, defeating Republican businessman Curtis Bashaw for the seat that opened when Bob Menendez resigned this year after his federal conviction on bribery charges.

Andy Kim, the millennial son of South Korean immigrants and three-term Democratic congressman, was elected to the U.S. Senate in a historic win that upended New Jersey politics and gives Kim the distinction of being the country’s first Korean American senator.

Mr. Kim, a Democrat, will take the seat previously held by Robert Menendez, who resigned after being convicted of taking bribes. By Tracey Tully and Erin Nolan Representative Andy Kim was elected on Tuesday to the U.S. Senate by a decisive margin ...