Craig Cathcart has joined the club from Manchester United for an undisclosed fee and has signed a three-year contract.
Ludovic Sylvestre joins the club from Mlada Boleslav and has signed a two-year contract with Blackpool.
Elliot Grandin joins the club from CSKA Sofia and has signed a two-year contract with the club.
French midfielder Malaury Martin has signed a one-year contract with Blackpool after impressing on trial earlier this summer.
