James Schiller scored 16 tries in 13 NSW Cup appearances this season, adding 64 tackle breaks and an average of 133 running metres per game.
The 25-year-old has signed with Parramatta for 2027, according to The Daily Telegraph, after Newcastle allowed him to explore other options.
News Corp had previously reported that Schiller was expected to join Wests Tigers.
His move comes as Josh Addo-Carr's future at Parramatta is in jeopardy and the Eels seek greater depth in their outside backs.
Schiller joined Newcastle from Canberra on a three-year deal in 2026 and is in the final year of that contract.
He played once in the NRL this season, running 105 metres and making six tackle breaks in a round-eight defeat to Penrith.
He was listed as Newcastle's unused 18th man in round 16 against St George Illawarra.
A neck injury meant surgery was scheduled for July, with a 4-6-week absence noted for this season.
Schiller also played in Newcastle's NSW Cup finals campaign, which ended with losses to Penrith and Newtown in consecutive rounds.
Parramatta have also signed Jarome Luai, Spencer Leniu and Jaydn Su'A for 2027 and are tipped to pursue further ambitious recruitment.