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.

"Tropical nights" forecast for the Channel Islands
Guernsey rabbits at risk from two deadly diseases
Exhibition to celebrate 90 Years of Guernsey's Ambulance Service
Guernsey sewage pipe repairs "unlikely to be a quick"
Guernsey FC to fight for promotion at Victoria Park
Move to return St Julian's House to Guernsey's emergency shelter
Jersey and Guernsey included in UK-Gulf trade deal
St Pier says States put investigation before his experience in P&R seat vote