Loch Dochfour

{{short description|Lake in Scotland}}

{{Use dmy dates|date=June 2023}}

{{Use British English|date=March 2025}}

{{Infobox body of water

| name = Loch Dochfour

| image =

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| pushpin_map = Scotland

| location = Scottish Highlands

| coords = {{coord|57|25|00|N|4|19|30|W|region:GB_type:waterbody|display=inline,title}}

| type = freshwater loch

| inflow = Loch Ness

| outflow = River Ness/Caledonian Canal

| length =

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| elevation = {{convert|15.8|m|abbr=on}}

| islands =

| cities = Lochend; Dochgarroch.

}}

Loch Dochfour is a freshwater loch in the Scottish Highlands southwest of Inverness, part of the Great Glen. The southern end flows in through the Bona narrows from Loch Ness. The northern end flows out through the River Ness and the Caledonian Canal towards the Beauly and Moray Firths to the North Sea.

As part of the construction of the Caledonian Canal supervised by Thomas Telford, the Ness Weir was constructed across the natural outflow just south of Dochgarroch. This raised the level of Loch Dochfour by almost {{Convert|2|m|spell=in}}, and the level of Loch Ness by {{Convert|1.2|m|abbr=on|spell=}}, making them equal in level. Before construction of the Caledonian Canal, Loch Ness ended at Lochend, flowing into the River Ness. This means that Loch Dochfour can be seen as that part of the River Ness upstream from the weir, or as an extension of Loch Ness northwards to the weir, or as part of the Caledonian Canal, or as a loch in itself. The Bathymetrical survey of the Scottish fresh-water lochs considered Loch Dochfour to be distinct from Loch Ness proper, but capable of being regarded as forming part of Loch Ness.{{cite book |title=Bathymetrical survey of the Scottish fresh-water lochs |chapter=Lochs of the Ness Basin |page=383 |chapter-url=https://archive.org/details/bathymetricalsur21910murr/page/382/mode/2up?view=theater&q=dochfour |date=1910}}{{cite web |title=Caledonian Canal |series=Canals and rivers – Waterscape |publisher=British Waterways |url=http://www.waterscape.com/canals-and-rivers/caledonian-canal |archive-url=https://web.archive.org/web/20120305135130/http://www.waterscape.com/canals-and-rivers/caledonian-canal |archive-date=5 March 2012}}{{Cite web |title=Safeguarding Caledonian Canal’s 200-year-old Ness Weir |url=https://www.scottishcanals.co.uk/about-us/maintaining-and-developing-the-canals/our-projects/safeguarding-caledonian-canals-200-year-old-ness-weir |access-date=2025-06-15 |website=Scottish Canals |language=en}}{{Cite journal |last=Brown |first=David H |date=March 2010 |title=Scottish canal reservoirs – a historical perspective. Part 3: Caledonian canal |url=https://www.icevirtuallibrary.com/doi/10.1680/dare.2010.20.1.39 |journal=Dams and Reservoirs |language=en |volume=20 |issue=1 |pages=39–43 |doi=10.1680/dare.2010.20.1.39 |issn=1368-1494|url-access=subscription }}

The A82 road runs adjacent to and in part on an embankment over Loch Dochfour.