Isi is a personal name; sometimes an abbreviation of Isidore, Isaac, Israel, Isabel, or Islam, or the equivalents in another language.

• Isi (footballer, born October 1995), Isaac Gómez Sánchez, a Spanish football midfielder
• Isi Gabsa (born 1995), Isabell Gabsa, a German professional golfer
• Isi Leibler (1934–2021), a Belgian-born Australian-Israeli Jewish activist
• Isi Metzstein (1928–2012), Isi Israel Metzstein, a German-born architect in Scotland
• Isi Naisarani (born 1995), Fijian–Australian rugby union player
• Isi Palazón (born 1994), Isaac Palazón Camacho, a Spanish football left winger
• Isi Ros (born 1995), Isidro Ros Ríos, a Spanish football winger
• Isi Siddiqui, Islam A. Siddiqui, American agricultural scientist and administrator
• Isi Tu'ungafasi (born 1995), Isileli J. Tu'ungafasi, Tongan–New Zealand rugby union player
• Isi Yanouka, Yitzhak Yanouka, Israeli diplomat