There are now four out gay men and women in the US House of Representatives after David Cicilline, a Democrat, won the Rhode Island congressional seat being vacated by retiring Representative Patrick Kennedy.
Democrats Tammy Baldwin, Barney Frank, and Jared Polis also retained their seats in the US mid-term elections.
Mr Cicilline, 49, is the out gay mayor of Providence, Rhode Island. He won the seat by 51 to 44 per cent.
One election leaflet described his opponent as a “husband and father” and Mr Cicilline as a gay man who wanted to legalise gay marriage.
He is only the seventh out gay person to join Congress and only the third to be elected while open about his sexuality.
Ms Baldwin, the representative for Wisconsin’s 2nd district, easily held on to her seat against Chad Lee, with 62 percent to 38 percent of the vote.
In Colorado’s 2nd district, Mr Polis saw off Tea Party-supported candidate Stephen Bailey with around 72 per cent of the vote.
Mr Frank retained his seat in Massachusetts’ 4th district for a 16th term, beating Sean Bielat. Indications said Mr Frank won his seat by 11 percentage points.