The ringed seal has a circumpolar distribution and is resident in North Pacific, North Atlantic and Arctic waters. Ringed seals use fast ice and sometimes dense pack ice for whelping, and numbers are strongly related to the relative permanence and density of ice in southern parts of their range. Pups are born in snow covered birth lairs, although ringed seals in the Okhotsk Sea regularly give birth on the exposed sea surface. Ringed seals have been seen within 2 km of the North Pole.
Females are slightly smaller than males.
The Baltic and Ladoga Lake subspecies are somewhat larger than the other subspecies. Adult coat colour is variable among subspecies, with rings on the sides and back. The subspecies hispida is illustrated above . Sexual maturity is attained in 5-7 years, males generally mature somewhat later than females. Gestation lasts 10.5-11 months.