Hester was raised on the Channel Island of Sark, educated at Elizabeth College Guernsey. Aged 19 he applied for a job with horses on the UK mainland at The Fortune Centre of Riding Therapy and on the centre’s skewbald mare, Jolly Dolly, he won the 1985 Young Dressage Rider Championship. Moving to Bourton-on-the-Hill he competed at the first Blenheim Horse Trials and won the Spillers Dressage with Jumping Championship. He next rode for Dr Wilfried Bechtolsheimer (father of Laura Bechtolsheimer) and in 1990 went to the World Championships on Rubelit von Unkenriff, the European Championships in 1991 and in 1992 the Barcelona Olympics on Georgioni. Hester became the youngest British rider ever to compete in an Olympic Games. He next went into a business partnership with Kate Carter at her yard at Stow-on-the-Wold until Carter decided to move for more space. Hester too moved to buy his own yard at Oaklebrook Mill, near Newent, Gloucestershire. In 2011 Hester riding the horse Uthopia was part of the British team that won the team gold medal at the 2011 European Dressage Championship in Rotterdam. Hester also won individual silver medals in the Grand Prix Freestyle and Grand Prix Special.As of 8 August 2012 the (FEI) rank him 12th in the world riding Uthopia.In 2012, Hester was selected with three others to represent the United Kingdom at the 2012 Summer Olympics in London in the Individual and Team Dressage events.The UK dressage team won the gold medal with Hester riding Uthopia.