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.

Majority of Guernsey stamps bought by collectors
Alex Scott withdraws from England squad
GST backlash prompts call for calm from Guernsey deputy
Deputies vote in GST at 3% as part of tax reform package
Man charged with murder of Hannah Benfield in Alderney
Deputy Inder apologises for raising middle finger to GST protestors
Guernsey employers face delay over work permits
Chris Kamara launches men's mental health initiative in Guernsey