The young Australian has been searching for a seat to continue in the world championship, but to no avail.
Earlier this year, Red Bull-backed KTM team Tech3 announced Roulstone would be replaced by Finnish rider Rico Salmena alongside incumbent Valentín Perrone of Argentina.
Roulstone, just 20 years old, suffered a broken neck before the 2025 season started.
Upon returning, he was a points scorer in every race that he finished – only suffering three DNFs.
After a breakthrough top five finish at Mandalika – his first in Moto3 across two seasons – Roulstone shone at his home grand prix at Phillip Island.
He was in early podium contention before crashing out, prompting an emotional outpouring.
Then a fall during practice at Sepang left him with a broken hand and meant he missed that race and the penultimate round at Portimao.
Roulstone has been given medical clearance to compete in the Valencia season finale, which will act as his swansong.
It will bring to an end two seasons in Moto3, and a career on Dorna’s MotoGP ladder that began in 2019 at just 14 years old in the Asia Talent Cup.
“Since a little kid, it has been a dream of mine to race for Red Bull KTM,” Roulstone wrote on social media.
“The dream started at my first motocross race on a KTM 50 and continued through racing flat track on their 65s, 85s and 125s.
“I had my first race in JuniorGP to my last Moto3 race this weekend. All while on a KTM.
“Unfortunately our path has come to an end, as well as my time in Moto3.
“It hasn’t been the easiest of roads that’s for sure, but I’ve been privileged to say that I raced for Red Bull KTM.”
Roulstone enters the season finale 16th in the Moto3 riders’ championship while teammate Perrone is 10th with two podium finishes to his credit.
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