McCready, 29, began his career with Crewe, joined Tranmere in 2006, but moved back to the Alex in 2007.
He joined Northampton last summer but was loaned back to Tranmere in January and joins Morecambe on a free.
Shrimps boss Sammy McIlroy said: "Andy is a very promising player who I am sure has a great career ahead of him while Chris has a lot of experience at this level which will be important to us."
Fleming spent four years at the Racecourse, playing 70 times for the first team, and established himself as a regular last season.
McCready made 18 appearances for the Cobblers last season but had slipped down the pecking order.
Boss Ian Sampson said: "His first team opportunities here would have been limited as we have a number of central defenders on our books who in all honesty would have been above Chris in the pecking order this season."
Source: BBC Sport
Source: BBC Sport