The 24-year-old, who made 39 appearances and scored 10 goals for the Isthmian Premier Division side last season, has signed a one-year deal at Griffin Park - his first professional contract.
"I had a good season last year at centre-back and scored a few goals too," he said.
"I didn't know it but the gaffer had watched me nine times overall - so I must have done something right."
Scott's preparations for the League One season have been further boosted after defender Mark Phillips signed a new one-year contract.
"I'm pleased to be staying with the club," said the 27-year-old.