More than 100 military vehicles, classic cars and tractors will follow the route around the coast.
The cavalcade begins at Torteval Church before following Guernsey's coast in a clockwise direction.
More vehicles, gathered at Pembroke, will join for the final leg of the route, through the Bridge and ending up on the seafront in St Peter Port.
Director of the Liberation Day Cavalcade Jeff Vidamour says the event is a staple in Guernsey's Liberation Day calendar.
"We know the cavalcade is one of the most popular parts of the day's celebrations. It is a wonderful event to be part of, and the vehicle owner's enjoy it as much as the people who line the route, waving their flags and cheering us past."
From 3pm to 5pm, islanders can get a closer look at the vehicles and speak with their owners at the static display on the seafront.
How Guernsey is celebrating 81 years of Liberation
Polls open in Guernsey's first island wide by-election
Iran effect looming in Guernsey's latest inflation figures
Alderney to explore data centre hosting
Prime Guernsey seafront location for sale
Woman (20) arrested on suspicion of attempted murder in Guernsey
New citizen science project observing Guernsey dragonflies and damselflies
