The Ton boss also revealed that striker Archie Campbell has agreed terms on a new one-year contract at Cappielow.
Dyer started his career at St Johnstone before moving to Brechin City, prior to a two year stint in Kirkcaldy.
And Moore boss was delighted to bring the 25-year-old left-back to Cappielow and believes he will prove a success at Ton.
He said: "He is a good, steady defender. I looked at his stats and he played 29 games for Raith this year and played 28 last year, when Raith finished second in the league.
"He is solid, he's dependable and he played well against us on Saturday so I think the supporters saw why we are very pleased to bring him in.
"He is a good height and a good age at 25 - he is hopefully somebody we can work on and improve in his time here.
"He also gets up and down the line on the left. With David O'Brien ahead of him and Michael Tidser just inside I think that gives us a good base on that side of the pitch."