Iwar Samuel "Iffa-Sven" Swensson (November 7, 1893 – June 18, 1934) was a Swedish football (soccer) player who competed in the 1912 Summer Olympics.
He was a member of the Swedish Olympic squad in 1912. He played as forward one match in the main tournament as well as one match in the consolation tournament. He scored two goals in the main tournament.