Gaston has been in scintillating form for Dungannon in the Ulster Bank League and has also impressed for the Ulster Ravens side in recent months.
The 20-year-old has been named in a back-line that also includes current Ireland Under-20 internationals Paddy Jackson, Craig Gilroy and Luke Marshall and Ireland Wolfhounds starlet Nevin Spence.
Luke Marshall returns to inside centre as Paddy Wallace is on Six Nations duty, while Jackson's inclusion at out-half sees Ruan Pienaar move back to his more familiar scrum half position with Paul Marshall dropping to the bench.
In the front row, Andi Kyriacou and Declan Fitzpatrick come in for Nigel Brady and Tom Court respectively.
The other change in the pack sees Robbie Diack pack down at number 8 in place of Pedrie Wannenburg. Stand-in captain Johann Muller continues his second row partnership with Tim Barker.
The squad is boosted by the return from injury of lock Dan Tuohy and centre Darren Cave, who are listed amongst the replacements.
Ulster Rugby would advise supporters coming to the game (gates open 5.30pm) to avoid parking in the immediate vicinity of the Ravenhill grounds and that the following roads are only accessible for residents and closed to everyone else - Onslow Parade, Ravenhill Park and Ravenhill Park Gardens.
There will also be parking restrictions in place in the Castlereagh area (Mount Merrion Avenue).
Supporters are encouraged to make use of the Park 'n' Ride facilities at Pirrie Park and along Montgomery Road and your co-operation is gratefully appreciated.
ULSTER (v Newport Gwent Dragons): Adam D'Arcy; Conor Gaston, Nevin Spence, Luke Marshall, Craig Gilroy; Paddy Jackson, Ruan Pienaar; Paddy McAllister, Andi Kyriacou, Declan Fitzpatrick, Johann Muller (capt), Tim Barker, Chris Henry, Willie Faloon, Robbie Diack.
Replacements: Nigel Brady, Bryan Young, Jerry Cronin, Dan Tuohy, Pedrie Wannenburg, Paul Marshall, Darren Cave, Tommy Seymour.