The men's 1st XV currently play in Regional 2 North West, at the sixth tier of the English rugby union system, following their promotion from South Lancs/Cheshire 1 via a play-off at the end of the 2016–17 season.

Cheshire Cup quarter-finalists on three occasions, Douglas joined the RFU National league in 1986–87 and have since been promoted to Regional Two North West.

The first Isle of Man club to build a clubhouse, subsequently extended with four changing rooms, showers, physio's room, gym, referees' facilities and kitchen, the 1st XV retained the Manx Cup for the fifth successive time in 2016–17 and were first to instigate Isle of Man mini rugby in 1994.

Under coach Tom Waterworth, the Celts won the 2019 Manx Cup in a tense final versus Ramsey 15–12 at Ballafletcher in monsoon conditions, and in doing so became the first second-string team to win the competition.

In 2021–22 Douglas retained their North One West status despite Covid and travel difficulties dictating an opening run of seven away fixtures before Christmas.