The 77-year-old Nobel Peace Prize winner died last week following an illness.
The peer and former leader of the Ulster Unionist Party played a key role in forging the 1998 Good Friday Agreement that ended decades of conflict in Northern Ireland.
Months after the deal was signed, Lord Trimble was jointly awarded the Nobel prize with late SDLP leader John Hume in recognition of their efforts to stop the bloodshed and establish a powersharing system.
Prime Minister Boris Johnson, Irish President Michael D Higgins and Taoiseach Micheal Martin all attended the funeral at Harmony Hill Presbyterian Church in Lisburn on Monday.
Below, GB News has put together a selection of pictures from the proceedings.
Prime Minister Boris Johnson, Irish President Michael D Higgins and Taoiseach Micheal Martin Liam McBurney
Former moderator of the Presbyterian Church, Charles McMullan speaking at the funeral Liam McBurney
Prime Minister Boris Johnson Liam McBurney
Sarah, Nicholas, Lady Daphne, Victoria and Richard Trimble Liam McBurney