Steve Lovell's side to travel to Wales in late January.
Gillingham's Emirates FA Cup fourth round game against Swansea City will be played at the Liberty Stadium on Saturday January 26 (3pm).
The fixture has not been selected for any television coverage.
Gills progressed to the next stage after defeating Cardiff City at Priestfield last weekend, with Elliott List netting an 81st minute winner.
Steve Lovell's men had already beaten Slough Town and Hartlepool United in the previous rounds.
Tickets are not yet on sale, however the prices will be as follows:
General sale
Adults - £15.00
Over 60s & Students - £12.50
Under 16s - £1
Matchday (all)
Adults - £20.00
Over 60s & Students - £15
Under 16s - £1
Prices increase for all purchases on matchday.