A connector assembly comprises a connector and a mating connector mateable with each other. The mating connector comprises a mating lock member having a mating lock portion. The connector comprises a holding member and a lock member. The holding member has a holding portion and a stop portion. The lock member has a held portion and a lock portion. The held portion is held by the holding portion. The lock portion is located below the mating lock portion and faces the mating lock portion in the upper-lower direction under the mated state. The coupling portion has an abutment portion. When the lock portion is moved toward the held portion in the first horizontal direction in accordance with removal of the connector from the mating connector, the abutment portion is brought into abutment with the stop portion so that a movement of the lock portion is restricted.