David signed for Brentford at the beginning of the 2015/16 season and has made a total of 25 appearances for Kevin O'Connor's B Team side since last term, including key matches on tour in Denmark, Germany and Italy.
Head of Football Operations Rob Rowan said: "David has really matured over the last 12 months, which had significant impact on his development as a footballer.
"Last season was challenging for him. The technical staff and I weren't sure if he was going to be able to adapt to the techincal and physical demands of training and games as one of the youngest members of the squad. However, since pre-season he has worked hard to develop himself and compete with Lukas Talbro for the starting place at right-back.
"David deserves this new contract and we look forward to working with him for the remainder of this season and next."