Ulster players Ruan Pienaar and Dan Tuohy will be part of the Barbarians side which faces Fiji at Kingspan Stadium on 11 November.
The game will see the Barbarians playing in Belfast for the first time in 59 years.
The Barbarians' autumn tour also includes a match against South Africa at Wembley six days earlier.
The only time the Baa-Baas had played in Belfast before was a match against an Ulster Invitation team in 1957.
Robbie Deans and Will Greenwood will coach the Barbarians, which is an invitational side made up of internationals and top club players.
Springboks star Pienaar, 32, is in his final season of action for Ulster after the IRFU refused to extend the scrum-half's seven-year deal with the Irish province.
The IRFU's decision caused a major outcry within Ulster supporters as the hugely popular South African admitted that he had wanted to remain with the Kingspan Stadium club.
Bristol-born lock Tuohy joined Ulster in 2009 and he has earned 11 Ireland caps.
The 31-year made his return to action after 10 months out in Ulster A's game against their Leinster counterparts last weekend.
Tuohy has been out since sustaining an ankle injury against Edinburgh last December.