The 28 year old was out of contract at Blackpool this summer and joined the Millers for an undisclosed fee.
Speaking to the clubs official website Tilt said; "I'm delighted to get this one over the line. It's been a long day, but hopefully I get to meet the lads on Saturday and see what it's all about, It's nice to know that you're wanted by people and that gives you a good feeling when you arrive, but to be honest, I tried to just stay out of it all whilst the two clubs concentrated on the business side of things."
"There's a couple of my former teammates here and it will be good to meet up with both of them. I still keep in close contact with Clark and Vass anyway, and I played together with Robbo at Blackpool where we had a solid partnership. Kyle Vassell is in form at the moment too, scoring goals, and you can see he's back where he wants to be. I spoke to both of them and they told me what a great club it is, how the gaffer works and what the team spirit is like here. That just helped me make my decision a little bit easier."
"It wont be easy, but I'm challenging myself to get into the team. Obviously the lads are winning and I'll support them no matter what, but it's up to me to fight for a spot."
"Every team has ambitions of getting into the Championship, but Rotherham are top of the league at the moment and fingers crossed we can get over the line and I can help us get there come the end of the season. I can't wait to get involved, introduce myself to people around the stadium, and then the hard work starts Monday down at the training ground."