To provide a coating agent for thread having high adhesiveness to the thread, improving appearance and smoothness and giving excellent strength, and to provide a thread coated with the coating agent.

The coating agent for thread contains a polyolefin resin (A) and a polyurethane resin (B); the polyolefin resin (A) is a copolymer containing an unsaturated carboxylic acid component (a1) and an ethylenic hydrocarbon component (a2); the content of the unsaturated carboxylic acid component (a1) in the polyolefin resin (A) is 0.01-10 mass%; and the glass transition temperature of the polyurethane resin (B) is 20C.