Ireland star announces retirement
The 33-year-old won 70 Ireland caps between 2005 and 2017, helping Joe Schmidt's men claim the 2014 Six Nations title.
Trimble, who has made a record 229 appearances for Ulster, also featured when Ireland claimed their maiden win over New Zealand in Chicago in November 2016.
In an open letter published by Ulster and the Irish Rugby Football Union, Trimble called time on a sparkling career that included 17 Test tries.
"I know that I've been incredibly fortunate to have realised not one of my dreams, but two of them – to play for Ulster and to play for Ireland," he said.
"These have been some of the most fulfilling days of my life and I feel nothing but gratitude for them."
Ulster's operations director Bryn Cunningham said Trimble should be proud of his lengthy top-level career, adding that he had been a "class act both on and off the pitch".
Harlequins wing Tim Visser, who scored 14 tries in 33 internationals, has announced his retirement from Scotland duty to focus on his club career.
"Playing for Scotland has been the biggest honour of my life. I feel it has been even more special by not being my country of birth but where I had grown to call home," said the Dutch-born player.