Masimov, 41, was a deputy prime minister and economics and budget-planning minister in the former government, which resigned Monday after three and a half years in office.
Speaking about Masimov's nomination, President Nursultan Nazarbayev said, "Karim Masimov has a clear vision of the tasks facing the government."
Masimov, who speaks five languages and studied at a U.S. business school, is widely perceived as an influential figure close to President Nazarbayev. He became a deputy premier of the oil producing country in January 2006.
Masimov worked as the chairman of two Kazakh banks, and is seen as a successor of former Prime Minister Danial Akhmetov's policies.
Nazarbayev nominated Aslan Musin as Masimov's only deputy, and former Prime Minister Akhmetov as the country's first civilian defense minister.
Nazarbayev said the decision on the former cabinet's resignation "was caused by the desire to bring in a new generation of executives."
"I offered Akhmetov the position of the first civilian defense minister, and he agreed," Nazarbayev told parliament, adding that former Defense Minister Mukhtar Altynbayev, who also resigned with the rest of the government Monday, would be appointed chief of the General Staff.
