Jenkins makes his first start for the region since October as Blues face a crunch clash in Pool 2 against the French giants.
Director of Rugby Phil Davies makes a total of five changes to the side that defeated Newport Gwent Dragons on New Year’s Day.
The other change in the pack is a recall for lock Chris Dicomidis, with Macauley Cook moving to the back row.
Gareth Davies starts at fly half, with Rhys Patchell ruled out through injury, while Chris Czekaj is named on the wing. Harry Robinson misses the game with a leg injury.
The final change sees Gavin Evans named at inside centre where he will form a new-look midfield partnership with Richard Smith.
Davies said: “Toulon will be smarting from last week’s defeat in the league and they won’t have been happy they lost the game to us in Cardiff earlier in the season. It’s a massive challenge and they will be extremely motivated. But it is one we are ready for.
“They have huge quality in the team they have got but we are going out there to try and win. We will do the best we possibly can and the attitude in the squad is terrific.
“Throughout the season we have got better without the ball and with it we have controlled it. We now need to finish more and get a few more tries. We have got to be aggressive with or without the ball to match what Toulon throw at us.”
Cardiff Blues: 15 Leigh Halfpenny, 14 Alex Cuthbert, 13 Richard Smith, 12 Gavin Evans, 11 Chris Czekaj, 10 Gareth Davies, 9 Lloyd Williams; 1 Gethin Jenkins (c), 2 Marc Breeze, 3 Benoit Bourrust, 4 Chris Dicomidis, 5 Filo Paulo, 6 Macauley Cook, 7 Josh Navidi, 8 Robin Copeland
Replacements: 16 Rhys Williams, 17 Sam Hobbs, 18 Scott Andrews, 19 James Down, 20 Ellis Jenkins, 21 Lewis Jones, 22 Dafydd Hewitt, 23 Dan Fish