The player-turned-pundit was recently admitted to hospital with sepsis.
Campbell was a title winner with the Gunners and a hero at Goodison Park after saving the Toffees from relegation in 1999.
Arsenal said in a statement: "We are devastated to learn that our former striker Kevin Campbell has died after a short illness.
"Kevin was adored by everyone at the club. All of us are thinking of his friends and family at this difficult time."
Everton said in a statement: "Everyone at Everton is deeply saddened by the death of our former striker Kevin Campbell at the age of just 54.
RIP Kevin Campbell
Read HERE
Campbell was a title winner with the Gunners and a hero at Goodison Park after saving the Toffees from relegation in 1999.
Arsenal said in a statement: "We are devastated to learn that our former striker Kevin Campbell has died after a short illness.
"Kevin was adored by everyone at the club. All of us are thinking of his friends and family at this difficult time."
Everton said in a statement: "Everyone at Everton is deeply saddened by the death of our former striker Kevin Campbell at the age of just 54.
RIP Kevin Campbell
Read HERE