Governor General Arthur Hanna officiated at the brief ceremony at Government House after receiving certification from electoral officials that the FNM had won 23 seats.
This resulted in that party wresting office from former Prime Minister Perry Christie, whose party, the Progressive Liberal Party won the remaining 18 seats in the 41 seat Parliament.
Mr. Ingraham, who is 59, previously served two parliamentary terms as Prime Minister between 1992 and 2002.
He pledged to uphold the dignity of the office and be true to the people of the 700 islands which make up the Bahamas.