The Great Scottish Swim, which was previously held at Strathclyde Country Park in Motherwell, is expected to attract more than 2000 entrants.
It will take place on Saturday, August 24.
The event had to be cancelled in 2012 after concerns were raised about water quality at Strathclyde Park.
But now the event, which is geared towards swimmers of all abilities, has found a new home at Loch Lomond.
Participants can choose from half mile, one mile or two mile swims. The event also includes an elite race which attracts world class swimmers.
Fiona Logan, chief executive of Loch Lomond and The Trossachs National Park Authority, said: "We're proud to be able to host the Great Scottish Swim."
Event director Alex Jackson, said: "The relocation of the Great Scottish Swim to the iconic location of Loch Lomond this year will provide a spectacular backdrop for world class races."
For more information visit greatswim.org/Scotland