"I am grateful for the invitation to attend the papal investiture in Rome with Vice President Biden, and would like to be able to join the trip," Boehner said in a statement on Thursday.
The White House announced the delegation on Wednesday, shortly after the Vatican named Francis the new pope, succeeding Pope Benedict XVI.
Boehner cited debating the federal budget and a visit by the prime minister of Ireland as reasons he would have to stay in the United States.
"Unfortunately, my duties in the House next week -- including hosting President Obama and the prime minister of Ireland at the Capitol on Tuesday, and the debate on the budget -- make that impossible," Boehner continued. "I wish the Vice President all the best in his journey, and hope he communicates the prayers and warm regards of every American, especially Catholics, to the first pope from the Americas."