According to Poland's state news agency PAP, Budka received 79% of all votes.
Around 9,400 party members from all over the country were entitled to cast their votes.
Among Budka's competitors were other prominent Civic Platform’s politicians including former culture minister Bogdan Zdrojewski, former defence minister Tomasz Siemoniak, and former interior minister Bartłomiej Sienkiewicz.
The four-year term in office of outgoing party leader Grzegorz Schetyna ends by the end of January.
Schetyna announced last week that he would not be running for the position of head of the grouping.
In December, the Civic Platform party picked deputy parliamentary Speaker Małgorzata Kidawa-Błońska as its candidate for the country’s presidential race next year.
The Civic Coalition, led by the Civic Platform (PO) party, won 27.40 percent of the vote and 134 seats in the lower house, in Poland's parliamentary elections, last october.
(tf)