The arrivals of Lee Bowyer and Darren Ambrose have pushed the Scotland international further down the pecking order and speculation linking him with a loan move has been rife, although his hometown club Motherwell were believed to be favourites.
Almondvale chairman Dominic Keane confirmed the deal, telling the Edinburgh Evening News: "Brian is joining us and we're pleased because we've been after him for a while.
"We had to be patient but it's paid off and we've got him here for an initial six months.
"Ideally, we'd like to extend that but we'll see how it works out."
The move represents an ideal opportunity for Kerr to press his claims for a regular place in the Scotland side, with Berti Vogts bound to be watching the SPL more regularly than FA Premier Reserve League.