Born in Toronto, Ontario, Hewitt attended Upper Canada College and the University of Toronto where he was a member of the Toronto chapter of the Beta Theta Pi fraternity. He was a champion boxer in his student years, winning the intercollegiate title at 112 pounds. Hewitt developed an early interest in the radio and as a teenager accompanied his father, W. A. Hewitt, on a trip to Detroit, Michigan to see a demonstration of radio technology sponsored by General Electric. He took a job with Independent Telephone Company, which manufactured radios, and left that job and university when his father—the sports editor of the Toronto Daily Star—told him that the Star was going to start its own radio station. Hewitt became a reporter at the paper, and was ready to go on the air when CFCA was launched. CFCA's first hockey broadcast was on February 8, 1923, although it was colleague Norman Albert who performed the play-by-play. Hewitt's first broadcast likely was February 16, of a game between the Toronto Argonaut Rowing Club and the Kitchener Greenshirts. Hewitt recalled the date as being March 22 in his own book, although there was no game scheduled for that night at the Arena Gardens. Hewitt's book also mentioned his first broadcast as being of a game between Parkdale and Kitchener, and the Argonaut Club was based in Parkdale, a neighbourhood of Toronto. He also mentioned that game as going into overtime which the Argonaut-Kitchener game did. On May 24, 1925, Hewitt and his father made what was said to be the world's first broadcast of a horse race. In 1927, he was invited as guest announcer to broadcast the first game from the new Detroit Olympia. Hewitt was part of the opening night ceremonies for Maple Leaf Gardens on November 12, 1931, and the specially designed broadcast ' gondola ' where Hewitt would broadcast from was brought into the plans with his input, and the blessings of then Toronto Maple Leafs owner Conn Smythe.
''Hockey Night in Canada''
For forty years, Hewitt was Canada's premier hockey play-by-play broadcaster for the General Motors, then later Imperial Oil Limited, Hockey Broadcast on Saturday nights. As the show was aired on Canadian national radio, Hewitt became notable for the phrase "He shoots, he scores!" as well as his sign-on at the beginning of each broadcast, "Hello, Canada, and hockey fans in the United States and Newfoundland." Hockey Night in Canada broadcasts from Toronto were simulcast on television from 1952 until 1963, with Hewitt handling the play-by-play up until 1958, at which point he handed the duties over to his son, Bill Hewitt. The elder Hewitt provided colour commentary of the Saturday night games after that, while continuing radio play-by-play of weeknight games. After 1963, Foster was solely on radio while Bill worked on television. In 1951, he started his own radio station in Toronto, CKFH, initially at 1400 kHz, until moving to 1430 in 1959. The station carried Maple Leafs games until losing the rights in 1978. In 1981, the station was sold to Telemedia and was renamed CJCL. He made a bid at purchasing CHIN in 1970.
A Canadian-style pub and grill restaurant was established in his name in Kaohsiung, Taiwan. Justin Kelly portrays Hewitt in the season two episode "Radio Daze" of the Canadian Broadcasting Corporation's Frankie Drake Mysteries series.
