The 21-year-old New Zealander signed for Stellies from Australian A-League Wellington Phoenix in August 2025.
He was largely used as a back-up keeper in the club’s DStv Diski Challenge side.
The former Roda JC player is reported to hae signed a three-year deal with the Buccaneers.
The player's representatives posted the announcement, saying: "Chapter for our client @dub_bn19 joining the @officialpsl_za champions @orlandopirates.
"Thank you to @stellenbosch_fc for the professionalism and role in Dublin's development thus far. The best is yet to come."
Boon arrives at Pirates following the exit of 28-year-old former Jomo Cosmos and TS Galaxy shotstopper Melusi Buthelezi.
Milford head coach Xanti Pupuma says his side's first game of their debut season against title-holders Orlando Pirates gave them the confidence they needed to compete in the Betway Premiership.
La Cure Waves head coach Jerome Thomas has backed Orlando Pirates to win the CAF Champions League.
Orlando Pirates coach Abdeslam Ouaddou has warned his players that individual showboating will not be tolerated if they are serious about challenging for the CAF Champions League title.
Orlando Pirates head coach Abdeslam Ouaddou has admitted the club could be forced to consider its options in the transfer market after being left with just one recognised right-back.
