The 25-year-old, who played for England in 2009 during a loan spell with Huddersfield, made his NRL debut in round one last season but went on to play just five more matches.
"We have come to a mutual agreement with Scott that allows him to go home to England where he'll be able to continue his rugby league career," Cowboys general manager of football Peter Parr said.
"We wish Scott, and his partner Emma, all the best in the future."
Moore could find a home at London Broncos, who are looking for a host of new faces after losing 16 members of last year's squad.
The Broncos have yet to announce any new signings but are reported to have agreed terms with 20-year-old Australian winger Denny Solomona, who was released from his contract with Melbourne Storm on Friday.
Solomona is a product of Melbourne's youth system and graduated to the first-grade squad for the 2013 season following some impressive performances with the club's Under-20s.