Frist will be joined by co-chairs Rep. Melissa Hart of Pennsylvania and Colorado Gov. Bill Owens.
The RNC rotates chairmanship of the Platform Committee between governors and members of Congress, according to tradition set in 1968.
"We are pleased that Majority Leader Frist, Representative Hart and Governor Owens will bring their leadership skills to the committee responsible for articulating the values and views of the Republican Party," RNC Chairman Ed Gillespie said in a statement.
Frist said he was honored to be selected for the post, and that the platform would highlight the party's values.
"Our platform will guide Republicans as we seek to create opportunities for all Americans through economic security, improved education and greater access to quality health care. It will also reflect our commitment to combating terrorism and defending America's homeland," he said in a statement.
The Democratic National Committee, whose convention convenes in two weeks, already has drafted a platform. The GOP's convention remains six weeks away.