Fredette was ranked among the nation's top 75 shooting guards by ESPN. com in high school. He was Glens Falls High School's all-time leading scorer, ranking 16th on New York's all-time scoring list, with 2,404 points. Until February 24, 2015, Fredette held the all-time Section 2 high school record, when he was surpassed by Lake George senior Joel Wincowski. Fredette was named first-team all-state by the New York State Sportswriters Association and the Times Union as a junior and senior. He had several memorable on-court moments in his career at Glens Falls, including 12 different 40-point performances in his senior season, and a shot against Voorheesville High School's Andrew Catellier in the season opener of his junior year in which he banked a three-pointer off the glass and in with his opposite hand to force overtime at the end of regulation.  In his senior season Fredette led his team to a 25–2 record and the Class A State Championship game which they lost, 58–48, to a Peekskill High School team led by future Syracuse University forward Mookie Jones. He played AAU for the Albany City Rocks alongside future Penn State University point guard Talor Battle and Mark Domaracki. Fredette averaged 25 points per game to help the Rocks to a third-place win over the Minnesota Magic at the 2006 AAU National Championships.