Longridge moves immediately on an emergency loan and will go into the Bairns’ squad for Saturday’s Ladbrokes Championship encounter with Dunfermline.
The 26-year-old has scored twice in 13 matches this season.
Falkirk manager Paul Hartley told his club’s website: “I am pleased to be able to bring Louis into the club.
“He is a player with a good pedigree having played a number of games in the Premiership.
“He is quick and will hopefully add a different dimension to our strikeforce.
“We need to score more goals to help us climb the table and I believe Louis to be capable of helping us do just that.”