I1, i1, or I-1 may refer to: * Haplogroup I-M253, a human Y-chromosome haplogroup occurring at greatest frequency in Scandinavia * Japanese submarine I-1, a 1926 Imperial Japanese Navy submarine * Motorola i1, a smartphone by Motorola * LB&SCR I1 class, a 1906 British class of 4-4-2 steam tank locomotives * Polikarpov I-1, a 1923 Soviet monoplane fighter * I1, a rank-into-rank axiom in mathematical set theory * I won, as it is pronounced similarly This disambiguation page lists articles associated with the same title formed as a letter-number combination. If an internal link led you here, you may wish to change the link to point directly to the intended article.