He turned professional in 1996. Dredge attempted to gain his card on the European Tour via the qualifying school in 1995 and 1996, the second time doing sufficiently well to gain a place on the Challenge Tour for 1997. Dredge has featured in the top 50 of the Official World Golf Rankings.
Dredge lost his full European Tour playing rights at the end of the 2012 season and failed to regain his card at qualifying school.
However, he retained conditional status for 2013. Illness and injury forced him to miss most of the 2013 season, but he was granted a medical extension for 2014, during which season he played in nine tournaments.
He recorded back-to-back second-place finishes, and regained his card for 2015 by finishing 81st in the Race to Dubai. 1991 Welsh Boys Championship European Tour wins (2) Challenge Tour wins (2) DNP = Did not play CUT = missed the half-way cut "T" = tied Yellow background for top-10.
Amateur Jacques Léglise Trophy (representing Great Britain & Ireland): 1991 (winners) Eisenhower Trophy (representing Great Britain & Ireland): 1992 Walker Cup (representing Great Britain & Ireland): 1993 Street Andrews Trophy (representing Great Britain & Ireland): 1994 (winners) Professional World Cup (representing Wales): 2002, 2003, 2004, 2005 (winners), 2006, 2007, 2008 Seve Trophy (representing Great Britain & Ireland): 2005 (winners), 2007 (winners).