Provided is a resin, a resin composition containing the resin, a cured product, a prepreg, a metal foil-clad laminate, a resin composite sheet, a printed wiring board, and a semiconductor device. Provided is a resin represented by Formula (T), wherein a parameter indicating a proportion of a structural unit having an indane skeleton is 0.55 or more and 1.00 or less, and a parameter indicating a proportion of a terminal double bond is 0.20 or more and 3.00 or less. In Formula (T), R is a group containing structural units represented by Formula (Tx).

##STR00001##

Provided is a resin, a resin composition containing the resin, a cured product, a prepreg, a metal foil-clad laminate, a resin composite sheet, a printed wiring board, and a semiconductor device. Provided is a resin represented by Formula (T), wherein a parameter indicating a proportion of a structural unit having an indane skeleton is 0.55 or more and 1.00 or less, and a parameter indicating a proportion of a terminal double bond is 0.20 or more and 3.00 or less. In Formula (T), R is a group containing structural units represented by Formula (Tx).

##STR00001##