Scott Keller began riding at age 6 and progressed quickly through the junior ranks, winning the Virginia Horse Show Assoc. junior hunter year-end award for three consecutive years, as well winning top placings in the Medal and Maclay finals. After graduation from Duke University, Scott continued winning in the amateur-owner division, with two VHSA year-end championships. He began showing jumpers with Barney Ward in his 20s and competed successfully on his first Grand Prix mount, Romeo, including top finishes in the WEF grand prix classes, as well as several Puissance classes. Scott then trained with Joe Fargis and Peter Leone in his late-20s and early-30s. This period culminated with his winning three Grand Prix events in 1999 and competing in the 2000 Olympic trials, all aboard Napolitano. After a few-year hiatus, Scott returned to competitive showing in 2005, and began competing as a professional in 2006. He competed in the 2008 Olympic Trials with Shine of Light.