The 19-year-old spent six months at Griffin Park last season where he made 25 appearances for the club.
Bees boss Uwe Rosler told the club's official website: "He fit in very well to our squad and our style of play last year. He knows what we do at Brentford and that will be an advantage to all of us.
"The left back position is very important in our diamond system.
"We have two or three options to play on the right side but only Scott Barron on the left. There will be very good competition between the two and that will make us better."