Buxton was captain of the Wigan Athletic Development Squad last season and can operate anywhere across the back line.
Manager Gary Rowett told BBC Sport: "Adam is a player we have liked for some time and we tried to sign him during the summer.
"We watched him for about 18 months and really liked what we saw. He is a player that I know will be able to cope with the demands of this league."
"He is a big lad and can play in a number of positions across the defence. At the moment, with one or two injuries, it was important that we got someone in to add to the numbers at the back."
Buxton has joined up with Burton in time to make his potential debut in their weekend FA Cup tie with Bournemouth.