An object of the present invention is to provide a toner binder and a toner that maintains offset resistance while having high gloss and that is excellent in low-temperature fixability, grindability, image strength, and heat-resistant storage stability. The toner binder of the present invention is a toner binder containing a non-linear polyester modified resin (A), wherein the non-linear polyester modified resin (A) is a modified resin having one or more carbon-carbon bonds crosslinking polyesters, and the toner binder has a loss tangent tan δ of 2 to 20 in the entire temperature range of 110°C to 130°C.