To provide a transmission ratio variable device and a steering device for vehicle which can suppress relative rotation of a motor shaft and a lock holder by shock in locking time.

The transmission ratio variable device includes: the lock holder 52 which is provided integrally with the motor shaft 30; a lock lever 53 which restricts rotation by forming an engaging pawl 63 for engaging to an engaging groove 56 of the lock holder 52; and a lock device 51 including a solenoid 54 for driving the lock lever 53 so that the engaging pawl 63 may be engaged to and released from the engaging groove 56. A torque limit ring 59 is provided for restricting or allowing relative rotation of the motor shaft 30 and the lock holder 52 on the basis of friction resistance. The lock lever 53 is formed by dividing it into a base 81 connected to the solenoid 54, and a head 82 in which the engaging pawl 63 is provided, and the base 81 and the head 82 are connected to each other by a connection mechanism 83 in which elastic deformation is possible.