Harrison Island may refer to:
Canada Harrison Island (British Columbia), a small island in Esquimalt in Juan de Fuca Strait between Macaulay Point and McLoughlin Point Harrison Island (Manitoba), a small island in Sasaginnigak Lake northwest of Atikaki Provincial Wilderness Park in eastern Manitoba Harrison Island (New Brunswick), a small island in French Lake northeast of Lower Burton Harrison Island (Northwest Territories), a small island between the Middle Channel and East Channel of the Mackenzie River north of Inuvik Harrison Island (Nunavut), a small island in eastern Hudson Bay near Quebec Harrison Island (Oliver Lake, Saskatchewan), a small island in Oliver Lake in northeastern Saskatchewan Harrison Island (Torwalt Lake, Saskatchewan), a small island near Torwalt Lake east of Wollaston Lake in northeastern Saskatchewan
United States Harrison Island (Maryland), a small island in the Potomac River near Leesburg, Virginia