The zoo says the tortoise — a critically endangered species — was hatched in June after 135 days of incubation and that staff used an ultra-sensitive microphone to monitor the embryo on a daily basis.
It describes the Burmese star tortoise as "one of the most beautiful tortoises in the world" with bright radiating yellow stripes that form a distinctive star pattern on the shell.
The zoo has been caring for four Burmese star tortoises since 2007, but this is the first time a fertile egg has been laid.
It was one of nine eggs that were laid back in January, but the zoo says none of the others turned out to be fertile.
The species has undergone a dramatic decline due to mass harvesting and the illegal pet trade.
The Toronto Zoo is a member of the Turtle Survival Alliance, which is involved in an international effort to breed and repatriate tortoises to Burma.