Watson was the first British girl to win the US Junior Open
Heather Watson has been named Aegon Junior Player of the Year at the British Tennis Awards ceremony in Roehampton's National Tennis Centre.
The 17-year-old became the first Briton to claim the US Open girls' singles title earlier this year.
She also climbed to a ranking high of junior world number three.
The Guernsey teenager said: "2009 has been a great year for me and I am looking forward to 2010 and playing on the Women's Tour more frequently."
Watson also secured her first senior ranking reaching a high of 559 in November.
World number four Andy Murray walked away with the player of the year award after reaching number two in the world rankings and winning six ATP events over the past 12 months.