Wigan Athletic Academy product joins MK Dons from St Johnstone
The 25-year-old centre-back - who has made 27 appearances for St Johnstone this term - becomes the Dons' fourth signing of the January transfer window.
Bolton-born Sanders turned professional with Latics in 2019, and was a member of the squad that started the 2020-21 campaign in administration.


After loan spells at Blyth Spartans, Southport and AFC Fylde, he joined Kilmarnock in 2021, before moving on to St Johnstone last summer.
"I wanted to come to a club that suited my style of play, and this certainly does," he said. "I'm still looking to develop, I'm not the finished article by any stretch of the imagination.
"I've spoken to the gaffer on several occasions, he's someone who can help develop my game and that's something I'm really looking forward to.
"I pride myself on my defensive duties first. But I do like to take the ball and pass it quite a lot. I can play the ball into midfield and pass out from the back.
"I've watched a few games and hopefully, my style of play will fit with what the guys have been doing."
Dons head coach Scott Lindsey added: "Jack is an exciting centre-back at a great stage in his career, it's clear to see he has a really high ceiling.
"He's already played a good amount of football this season so should be able to hit the ground running quickly. We think he'll offer us something a little bit different at the back so I'm really looking forward to working with him."