The States will make all bus journeys, except night buses, free from Friday 7 July to Friday 14 July.
The move is designed to help the visiting teams move easily around Guernsey, as the sports venues to be used are dotted around the island.
At least 3,000 athletes and team support staff will be travelling to Guernsey ahead of the opening ceremony on 8th July, which is along the St Peter Port sea front.
Deputy Andy Cameron is a member of the Committee for the Environment & Infrastructure, and the political lead on Sport for the Committee for Education, Sport & Culture.
He says free buses should help keep the roads clear:
"We’ll have a lot of visitors at a time when there will be a significant number of road closures and suspension of public parking to facilitate the events, so we’re keen to do what we can do to reduce pressure on our road network and avoid potential congestion.
We want the Games to be a positive experience for everyone in Guernsey, whether they live here or whether they’re visiting for the first time."
The free buses will run to the last Friday of the Games, 14 July, but journeys on weekend night buses will still be charged.

Protestors to meet deputies ahead of Guernsey's GST debate
Venue change for World Cup semi-final screening in Guernsey
Discarded glass blamed for Little Sark fire
Appointment of Guernsey's first female Bailiff
Sensitive demolition at Guernsey's largest building site to begin soon
Private fostering laws could be updated in Guernsey and Alderney
Guernsey big screen for World Cup Semi-Final sold out
Hundreds protest against a goods and services tax for Guernsey