Tusk, who heads the center-right Civic Platform party, replaces the president's twin brother Jaroslaw as premier. Jaroslaw Kaczynsky resigned with his government on Monday following his conservative, nationalist Law and Justice party's election defeat last month.
Tusk, 50, will be formally appointed after lawmakers vote to approve a new cabinet next week. He is in talks with the Peasants' Party (also translated as the People's Party), led by Waldemar Pawlak, on forming a majority coalition.
Pawlak's party could receive the posts of deputy prime minister and economics minister in the new government. The two parties together have 240 seats in parliament, more than the 231 votes needed to approve a government.