I-1

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