Jackson, 32, started out at Chesterfield and has played for several clubs, including Alfreton Town, FC Halifax Town and a previous spell with Grantham.
Matlock boss Dave Frecklington said of his departing player: “I’ve got a lot of time for Jamie. He’s been unfortunate in some ways in the fact Westy Marshy and Luke have got 40 goals between them and with Margetts getting three in three games it’s been difficult for him to break into the team. He’s a great lad and I wish him nothing but the best.”
Jackson scored 15 goals in 110 appearances for the Gladiators, including three this season.
Grantham travel to Hednesford on Saturday, while Matlock Town host North Ferriby United.
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