The 23-year-old joins the Griffin Park club and will be made available for The Bees' home clash against Plymouth Argyle on Tuesday evening.
The Wimbledon-born left-back was a Palace trainee before signing a professional contract with the Selhurst Park club in May 1998.
With Leo Roget out with a long-term injury and Ibrahima Sonko away on international duty with Senegal's Under-21 side, Frampton's addition will help Brentford boss Wally Downes with some added defensive cover.
Roget and Sonko were absent last Saturday when The Bees came back from their trip to Stockport County with an excellent 3-2 victory at Edgeley Park.
