Loch Duntelchaig is a freshwater loch in the traditional county of Inverness-shire in the Scottish Highlands. It extends 5 km from the southwest to its outflow in the northeast and measures up to 1.75 km at its widest. The loch drains via Loch a Chlachain into the River Nairn. Loch Duntelchaig is over 60m deep towards its south end. It is also the main reservoir for Inverness sitting less than a kilometre from the secondary reservoir Loch Ashie.