In 2015, Luke Letcher partnered with Tom Schramko in the Men's Double Scull, however it was the following year, in his third U23 team, the following year that he won his first gold medal. The tall Canberran raced in the U23 Men's Quadruple Scull alongside Schramko, Rob Black and Caleb Antill, and won gold in Rotterdam, The Netherlands at the World Rowing U23 Championships. In 2017, Letcher's success in underage competition saw him step up into the senior rowing environment and selected into the Reinhold Batschi Men's National Training Centre. Letcher was then selected to race in the Men's Double Scull, with David Watts, for the 2017 World Rowing Cups 2 and 3 and the World Championships. In 2018, Letcher was selected in the Men's Quadruple Scull for the World Rowing Cups 2 and 3 - alongside fellow Canberra-local, Caleb Antill, David Watts and Alexander Purnell. Post World Rowing Cups, Letcher was selected into the Men's Single Scull for the World Rowing Championships. Outside of the high performance environment, Letcher is studying Systems Engineering at the Australian National University and enjoys mountain biking around Canberra as well as settling in to watch some Netflix. The tallest member of the RBNTC also enjoy a trip to Bunnings on a Sunday and says his favourite place to row is his hometown lake, Lake Burley Griffin in the Australian Capital Territory. In 2021, he joined Caleb Antill, Jack Cleary and Cameron Girdlestone racing in the Australian Men's Quadruple Scull that won bronze at the rescheduled Tokyo 2020 Olympic Games.