"France will stand with Burkina Faso during this key period of its history", said Hollande in a statement released on Monday.
Hollande has welcomed a "transition charter" - signed on Sunday between military, civilian, opposition and religious figures - that should drive the country to November 2015 free elections.
Kafando's appointment came two weeks after mass protests brought down the 27- year long regime of Blaise Compaoré and the military seized power.
"It is an awesome responsability that falls on me", said Kafando, 72, to reporters, "this appointment is more than an honour", he added.
After hours of negotiations, officials chose Kafando over other candidates - including journalist Cherif Sy and sociologist and ex-minister Joséphine Ouedraogo.
"The consensus candidate is Michel Kafando" said Ignace Sandwidi a representative of the Catholic Church involved in the negotiations.
Kafando served as ambassador to the United Nations from 1998 to 2011 and was also Burkina Faso's foreign minister in 1982-1983.
Under the deal, he will appoint a prime minister and 25 members to form a transitional government and a civilian parliament will stand as a National Transitional Council.