Yes. The Russian Zvezda K-37 seat system was specifically developed for use in the Kaman Ka-50 Black Shark, and is also used in the Ka-52 Alligator attack helicopter.
The seat is more of a tractor rocket system than a full ejection seat, but it does provide for escape from the helicopter. The system first fires explosive bolts to jettison the rotor blades then jettisons the canopies and finally tractors the crewmen out. Their parachutes automatically deploy seconds later.
In the United States, some work was done on a similar concept using an AH-1 Cobra helicopter, and a crew module system was tested on an H-21. Neither was followed up on.