The New Jersey Republican and House Armed Services Committee member beat out Adler with 53 percent of the vote to lock in the win in the 3rd Congressional District.
Adler, who was serving as a councilwoman in Cherry Hill, N.J., challenged Runyan after her husband's unexpected death due to complications from staph infection in 2011.
Democratic congressional leaders considered the race an uphill battle, declining to spend any campaign cash in the district in the weeks running up to Tuesday's election.
Behind in the polls in the run-up to Tuesday's election, Adler's camp ran a series of controversial radio ads comparing Runyan's work in Congress to Hurricane Sandy, the "superstorm" that ravaged New Jersey and the East Coast in October.
Runyan played eight years as an offensive lineman in Philadelphia and was part of the Eagles' 2004 team that lost to the New England Patriots 24-21 in Super Bowl XXXIX. He retired from the NFL in 2009 as a member of the San Diego Chargers.