Jolie and Pitt were apparently shopping for their brood of six children when they spent hundreds of pounds at the club shop, buying shirts, mugs, tracksuits and caps.
A source told The Sun: "They rang the club shop and spent hundreds. Son Maddox is a big fan and his favourite player is Steven Gerrard."
Jolie, 36, is known as a Liverpool supporter, and her son Maddox, 11, has also been known to sport a red jersey.
Both mother and son spent time filming in the Merseyside area in 2002.
The Hollywood stars are spending the festive period in the US, having spent a large proportion of 2012 living in Surrey.