Otter Lake is a lake in geographic Foley Township[2] in the municipality of Seguin, Parry Sound District in Central Ontario, Canada.

[1] Otter Lake was originally named 'Nigge-Cu-Bing' (Lake of Many Otters) by the original First Nations inhabitants.

[3][4] The unincorporated places and railway points of Otter Lake[5] and Holmur[6] are at the narrows and on the north side of the lake respectively.

The water level is controlled by a dam at the outflow to the Boyne River at the Little Otter portion of the lake.

[3] The Canadian Pacific Railway and Canadian National Railway main lines both pass the lake, the former at Otter Lake Narrows and the latter on the north shore of the lake.