Kaif, 31, will be walking the red carpet on the first day of the 12-day fest (May 13-24) as the ambassador of cosmetic brand L'Oreal Paris and also be a part of the opening ceremony.
"Such a fun day with the gorgeous Sonam Kapoor at the LOrealParisIn press conference! #CantWaitForCannes," read Katrina's first tweet.
Katrina will join actresses Sonam and Aishwarya Rai Bachchan, who have represented L'Oreal Paris at Cannes on previous occasions too.
Sonam welcomed the "Bang Bang!" actress on Twitter.
Aishwarya will attend the event on May 17 and 20.