The Kennington-based club get a second chance to take home the trophy following last year's failure, which resulted in Gloucestershire taking the crown by six runs with a total of 220.
Roy, who scored 497 runs for England's one-day team in the summer, heads into this weekend's contest having scored a century in the Championship at Durham earlier in the season.
"It's a special occasion," ECB's official website quotes Roy as saying. "I've got a 50% record. Unfortunately last year we got pipped at the final hurdle by Gloucestershire. Well deserved, obviously, on the day they played the much better cricket.
"But it's an incredible place to come and play whether it be a final, a normal game, a club game or whatever - if you get the chance to walk out here it's incredible.
"On the day you might get off to a flier, you might get a few early boundaries, on another day you might be stuck on nought for a while. But I suppose that's why they are called partnerships and hopefully your mate at the other end can help you out. Just go out there, enjoy yourself, trust your training, trust your game and trust that if you nail your skill you'll get your team off to a flier."
It is expected to be a tight clash between the teams given that they have produced an identical record in this competition, and that reflects in the betting odds as both are 10/11 to win.
Both Surrey and Warwickshire won four, lost three and failed to record a result in one of their eight matches, and the teams were only 12 months apart when they last claimed the trophy in 2010 and 2011 respectively.
Warwickshire got past Essex with a 70-run triumph in the quarter-finals and then went on to oust Somerset by eight runs in their semi-final showdown.
As for Surrey, a one-wicket win over Northamptonshire pushed them into the last four, and beating Yorkshire by 19 runs cemented a spot in the final.