A glass fiber-silsesquioxane composite molded article, comprising: glass fiber; and a cured product of silsesquioxane polymer that forms a composite with the glass fiber, wherein the silsesquioxane has a cage structure or partial cage structure, wherein said glass fiber-silsesquioxane composite molded article is obtained by impregnating glass fiber with a silsesquioxane having a polymerizable functional group or with a polymer thereof and subjecting the resultant to a curing reaction, wherein: the silsesquioxane having said functional group is selected from the compounds represented by the following general formula (A-2) or (A-3); and the glass fiber-silsesquioxane composite molded article is obtained by impregnating glass fiber with a composition containing at least one kind of said compounds, and a curing agent, a polymerization initiator or a hydrosilylation catalyst, or with a composition formed of the polymer of the silsesquioxane and a solvent, and subjecting the resultant to a curing reaction: in the general formulae (A-2) and (A-3): R independently represent hydrogen; an alkyl having 1 to 45 carbon atoms in which any hydrogen may be substituted by fluorine and nonadjacent -CH 2 - may be substituted by -O- or a cycloalkylene; a cycloalkyl having 4 to 8 carbon atoms; or an aryl in which any hydrogen may be substituted by an alkyl having 1 to 10 carbon atoms, halogen, or fluorine; R 1 independently represent a group selected from an alkyl having 1 to 4 carbon atoms, cyclopentyl, cyclohexyl, and phenyl; and in the general formula (A-2), at least one of X represents hydrogen, a vinyl group, or an alkylene having 1 to 10 carbon atoms, a cycloalkylene, or phenylene having a polymerizable functional group, and the remainder of X represents a group defined in the same manner as R 1, and in the general formula (A-3), at least one of X represents an alkylene having 1 to 10 carbon atoms, a cycloalkylene, or phenylene having a polymerizable functional group, and the remainder of X represents a group defined in the same manner as R 1, and the polymerizable functional group in the general formula (A-3) is selected from the following formula (b) to (e), or acryl, or (meth)acryl, wherein in the formula (b) to (e), R 2 represents an alkylene having 1 to 10 carbon atoms, one -CH 2 - in this alkylene may be substituted by -O- or 1,4-phenylene and R 3 represents hydrogen or an alkyl having 1 to 6 carbon atoms. glass fiber; and a cured product of silsesquioxane polymer that forms a composite with the glass fiber, wherein the silsesquioxane has a cage structure or partial cage structure, wherein said glass fiber-silsesquioxane composite molded article is obtained by impregnating glass fiber with a silsesquioxane having a polymerizable functional group or with a polymer thereof and subjecting the resultant to a curing reaction, wherein: the silsesquioxane having said functional group is selected from the compounds represented by the following general formula (A-2) or (A-3); and the glass fiber-silsesquioxane composite molded article is obtained by impregnating glass fiber with a composition containing at least one kind of said compounds, and a curing agent, a polymerization initiator or a hydrosilylation catalyst, or with a composition formed of the polymer of the silsesquioxane and a solvent, and subjecting the resultant to a curing reaction: in the general formulae (A-2) and (A-3): R independently represent hydrogen; an alkyl having 1 to 45 carbon atoms in which any hydrogen may be substituted by fluorine and nonadjacent -CH 2 - may be substituted by -O- or a cycloalkylene; a cycloalkyl having 4 to 8 carbon atoms; or an aryl in which any hydrogen may be substituted by an alkyl having 1 to 10 carbon atoms, halogen, or fluorine; R 1 independently represent a group selected from an alkyl having 1 to 4 carbon atoms, cyclopentyl, cyclohexyl, and phenyl; and R independently represent hydrogen; an alkyl having 1 to 45 carbon atoms in which any hydrogen may be substituted by fluorine and nonadjacent -CH 2 - may be substituted by -O- or a cycloalkylene; a cycloalkyl having 4 to 8 carbon atoms; or an aryl in which any hydrogen may be substituted by an alkyl having 1 to 10 carbon atoms, halogen, or fluorine; R 1 independently represent a group selected from an alkyl having 1 to 4 carbon atoms, cyclopentyl, cyclohexyl, and phenyl; and in the general formula (A-2), at least one of X represents hydrogen, a vinyl group, or an alkylene having 1 to 10 carbon atoms, a cycloalkylene, or phenylene having a polymerizable functional group, and the remainder of X represents a group defined in the same manner as R 1, and in the general formula (A-3), at least one of X represents an alkylene having 1 to 10 carbon atoms, a cycloalkylene, or phenylene having a polymerizable functional group, and the remainder of X represents a group defined in the same manner as R 1, and the polymerizable functional group in the general formula (A-3) is selected from the following formula (b) to (e), or acryl, or (meth)acryl, wherein in the formula (b) to (e), R 2 represents an alkylene having 1 to 10 carbon atoms, one -CH 2 - in this alkylene may be substituted by -O- or 1,4-phenylene and R 3 represents hydrogen or an alkyl having 1 to 6 carbon atoms.