Career
Riethmuller played his junior football for the Tully Tigers. Before playing for the Cowboys, he played for the Ipswich Jets and the Northern Pride in the Queensland Cup. He made his NRL debut against the Manly-Warringah Sea Eagles in round 14 of the 2011 season, at the age of 26, having broken into the Cowboys" first-grade squad after performing well in the Queensland Cup.
He signed a new two-year contract with the Cowboys shortly after his debut.
He qualified for the Italian team by virtue of having an Italian grandfather. Reithmuller made 21 tackles in just 19 minutes on the field in his debut game.
Reithmuller has represented the Queensland Residents on three occasions, scoring 2 tries. In 2012 he was named in the Queensland Residents side.
In 2015, Riethmuller is playing for Cairns Brothers in the Cairns District Rugby League Competition.
Joel is an Australian Apprenticeships Ambassador for the Australian Government and an Apprentice Mentor in the NRL"s Trade Uttar Pradesh With The NRL Program.