The choice of Park, whose father Park Chung-hee was president from 1961 until his assassination in 1979, was announced at the conservative party's convention, Voice of America reported.
She is the first woman to become the presidential candidate of a major political party in South Korea.
During her 15-minute acceptance speech, Park, 60, acknowledged that South Korea faces many problems, including the global economic crisis and threats from North Korea, but said she is prepared to confront them.
The main opposition Democratic United Party is set to announce its candidate in September. The DUP's front-runner for the December election is Moon Jae-in.
Under South Korean law, current President Lee Myung-bak cannot run for re-election.