His main rivals are Frenchman Tony Estanguet and Slovakian Michal Martikan, who won gold in Beijing, but Florence will hope he can carry over his form from earlier in the season.
He is last up in both his heat runs, and will be out on the course at 2.18pm and 4.35pm.
Only the best run will count towards ensuring qualification for the finals, but Florence is eager to start his bid for Olympic glory.
He said: 'I'm just looking forward to getting the racing under way and enjoying myself, it's going to be something that I will remember and cherish for the rest of my life.'
Richard Hounslow, Florence's partner in the C2, will also be hoping to make it safely through the heats.
Speaking ahead of the race he added: 'This is without a doubt the highlight of my career so far.
'I'm very lucky that this is my first Olympic Games and also a home Games as well. Even if it turns out to be my only Olympics I'm just so proud that I'll be able to compete in front of a home crowd, with my friends and family watching.'