Born in St. Maergen in Germany's Black Forest region, Fabian earned the respect of his teammates and praise from the coaches for his abilities in the cross-country part first and foremost. Riessle was "infected" with the Nordic Combined virus by his brother Philipp and already hat a first career highlight in 2010, when he won a team gold medal at his "home" Junior World Championships in Hinterzarten. In the same year, he won the overall ranking of the Continental Cup and since the 2011/12 season, he has been a member of the A-team in the World Cup.
Rießle who, is described by his teammates as always being in a good mood but still ambitious and focused, had his breakthrough season in 2011/12 when took his first two podiums results and an overall rank 14. Since this winter, he has been on the podium in every season. He spectaculary captured an individual bronze medal at the Olympics in Sochi when he and teammates Johannes Rydzek and Björn Kircheisen collided in the last turns before the finish. Riessle was also part of the silver-winning German team.
Rießle took another big step in the winter of 2014/15 when he was on an individual podium seven times and also won the team gold medal at the World Championships in Falun. He finished the season as fourth in the World Cup overall standings. The still missing individual victory finally became a reality in Lillehammer in December of 2015 and "Rio" followed up with two more victories in Chaux-Neuve and Lahti, ultimatly putting him on the World Cup overall podium of the winter as well.
The winter of 2016/17, Rießle ended up just off the overall podium, when Japan's Akito Watabe took the third place from him in the last race of the season. Still, Rießle had two more individual victories and a total of eight podium result to show for, forming a part of the almost unbeatable German team.
In his leisure time, Fabian, who is called "Rio" by his friends, likes to snowboard, listen to music and meet friends.