Gloucester back Tom Marshall and South African forwards Franco Mostert and Franco Marais are all leaving at the end of June to play in Japan.
New Zealander Marshall, 29, has been a regular this season, scoring seven tries in 17 matches and only signed a new contract in February.
Springboks lock Mostert, 29, and hooker Marais, 27 both joined in 2018.
Australia hooker James Hanson has, though, agreed a new contract with Gloucester for 2020-21.
The 31-year-old first joined the club on a short-term deal in 2017, and has played 32 games so far.
"We were aware that he had been exploring options with other clubs, but when we sat down with him and outlined our vision for the future, and the part we saw him playing in it, it was clear that he wanted to stay," said cheif executive Lance Bradley.
Of the three leaving, a club statement said: "We are extremely grateful for their hard work and contribution during their time."
Phone: (800) 737. 6040
Fax: (800) 825 5558
Website: 
Email: 
