Disclosed is a glass fiber-silsesquioxane composite molded article containing glass fibers and a cured material of a silsesquioxane polymer composited therewith, wherein the silsesquioxane has a polyhedral structure or a partially polyhedral structure. The glass fiber-silsesquioxane composite molded article is preferably obtained by impregnating glass fibers with a composition containing at least one of silsesquioxanes represented by formula (A-1) to (A-3) and at least one of a curing agent, a polymerization initiator, and a hydrosilylation catalyst, or the silsesquioxane polymer and allowing a curing reaction to proceed.