Debutant Fitzgerald has recovered from a chest infection and a knee injury to form an exciting all-Irish centre pairing with Keith Earls, who is back to fitness after sustaining shoulder damage in last Saturday's win over the Royal XV.
In total, there are five Irish players in the Lions starting line-up, headed by tour captain Paul O'Connell, while Ireland backs Ronan O'Gara and Gordon D'Arcy will be on bench duty in Bloemfontein.
D'Arcy, called up to the tour as midfield cover, linked up with the Lions squad in Johannesburg on Thursday having flown over from San Francisco where he was holidaying.
Lions tour manager Gerald Davies said: "The starting XV to play the Cheetahs is an interesting one with club and country combinations in many areas.
"The boys who played against the Golden Lions put down a marker in terms of the way we want to play and I know those playing against the Cheetahs will be very keen to keep the momentum going and produce another strong Lions performance."
Commenting on the team selection, head coach Ian McGeechan said: "With the selection of Donncha O'Callaghan, Leigh Halfpenny and Luke Fitzgerald in the starting side, it means that all the squad players will have taken to the field according to plan.
"We also have new arrival Gordon D'Arcy on the bench which gives him a chance to get straight into the action.
"Although there are no players backing up from the team against the Golden Lions, several of the replacements who saw action in that match have now been selected for their first start.
"For the Cheetahs match, Andy Powell, Stephen Ferris, Euan Murray, Ross Ford, Harry Ellis and James Hook are all in the starting line-up for the first time.
"The team includes an all-Welsh back three, an Irish combination in midfield and a Munster second row pairing.
"We are also are continuing to build partnerships and combinations among the players from the four nations and this is reflected in the front row where Scottish team-mates Euan Murray and Ross Ford will pack down in the front row alongside Andrew Sheridan.
"And the back row where three players from three different nations will play alongside each other."
BRITISH & IRISH LIONS TEAM/REPLACEMENTS (v Free State Cheetahs, 2009 Lions Tour, Saturday, June 6, Vodacom Park, Bloemfontein, kick-off 3pm local time/2pm Irish time):
15. Lee Byrne (Ospreys/Wales)
14. Leigh Halfpenny (Cardiff Blues/Wales)
13. Keith Earls (Munster/Ireland)
12. Luke Fitzgerald (Leinster/Ireland)