A repetitive two‐stage light gas gun for high‐speed pellet injection has been developed at Oak Ridge National Laboratory. In general, applications of the two‐stage light gas gun have been limited to only single shots, with a finite time (at least minutes) needed for recovery and preparation for the next shot. The new device overcomes problems associated with repetitive operation, including rapidly evacuating the propellant gases, reloading the gun breech with a new projectile, returning the piston to its initial position, and refilling the first‐ and second‐stage gas volumes to the appropriate pressure levels. In addition, some components are subjected to and must survive severe operating conditions, which include rapid cycling to high pressures and temperatures (up to thousands of bars and thousands of kelvins) and significant mechanical shocks. Small plastic projectiles (4 mm nominal size) and helium gas have been used in the prototype device, which was equipped with a 1‐m‐long pump tube and a 1‐m‐long gun barrel, to demonstrate repetitive operation (up to 1 Hz) at relatively high pellet velocities (up to 3000 m/s). The highest experimental velocity is twice that available from conventional repeating single‐stage pneumatic injectors that accelerate frozen pellets of hydrogen isotopes and are now used to fuel magnetically confined plasmas for controlled thermonuclear fusion research. Also, the pellet test repetition rate of 1 Hz is relevant for fueling applications on future large fusion research devices. The equipment is described, and experimental results are presented and compared with calculated results from gas dynamics models.