Under Louisiana's "jungle primary" system, all candidates appeared on the same ballot, regardless of party, and voters could vote for any candidate.

Since no candidate received a majority of the vote during the primary election, a runoff election was held December 10[1] between the top two candidates in the primary, Republican John Neely Kennedy and Democrat Foster Campbell, where Kennedy won with 60.65% of the vote, giving Senate Republicans 52 seats in the 115th Congress.

Louisiana is the only state that has a jungle primary system (California and Washington have a similar "top two primary" system).

Incumbent Republican Senator David Vitter unsuccessfully ran for Governor of Louisiana in 2015,[2] and in his concession speech he announced that he would not seek re-election to the Senate in 2016.

[3] In addition to Kennedy and Campbell, four other candidates — Republicans Charles Boustany, John Fleming, and David Duke, and Democrat Caroline Fayard — qualified to participate at a debate at Dillard University, a historically black college, on November 2, 2016[4][5] This election is the most recent United States Senate runoff election in Louisiana as of 2024.