He was 64.
The CBC says Carew was found at his home on Monday and had suffered from serious health problems.
Carew was planning to retire in September, telling his listeners in May when he announced his departure that hosting the program was the best job he ever had.
The public broadcaster says Carew had planned to spend more time on his music, having released four albums since 1997 and performing with his band the Magpies at benefit concerts across the Maritimes before they disbanded in 2012.
Denise Wilson, senior managing director for CBC Atlantic, said she and Carew's colleagues were shocked and saddened by news of his death.
"Stan was a mainstay in households throughout the Maritimes as host of CBC Radio's Weekend Mornings," she said in a statement.
Carew began his career in radio in 1968 at CHNS in Halifax and worked for the CBC in Saint John, N.B., and Toronto.
The CBC says Carew worked as an actor too, appearing in movies that featured Harrison Ford, Sissy Spacek, James Caan and Cybill Shepherd.
His television credits include "Trudeau" and "Trailer Park Boys."
Carew was also the host of the CBC network shows "The Entertainers" and "Prime Time," as well as reading national newscasts on the "World at Six" and "World Report."