The club made the decision following Wednesday night’s 2-1 defeat to Stockport County in the live BT Sport match.
It means Pools had won just one of their last seven National League games, leaving the club in 16th position.
A club statement confirmed: "Hartlepool United has today made the decision to terminate the contracts of Craig Hignett and Assistant Manager Ged McNamee.
"A more detailed statement will follow this afternoon but suffice to say this incredibly difficult decision has been made with a heavy heart, as both men have worked tirelessly for the Club in the last eighteen months."
Hignett took over for the second time at the end of January and a number of impressive summer signings gave confidence to a push for promotion.
But things haven’t worked out as planned with the club in the lower half and struggling for form.
Hartlepool travel to Aldershot Town on Saturday.