The 16-seater minibus is being leased for three years using £75,000 from the HS2 Community and Environment Fund to provide transport while construction work takes place alongside the village.
Villagers have already started to make use of it and a service to Brackley is underway. A very successful trip to Buckingham was made last week. Clubs and community organisations have also started to use the minibus and so too has the village school.
There is so much demand that extra volunteer drivers are being trained through the Greatworth Community Transport Association, which is run entirely by volunteers. The bus will be used by all age groups and also for the disabled. It has lift access for wheelchair users.
Association spokesman Richard Edwards said: "The minibus will help the village community through a difficult period when the HS2 construction work necessitates the closure of a main access road into the village for a considerable time. Greatworth has no bus service so the minibus will be of practical help to our residents and make them feel less isolated during the major part of the construction work."
"It has taken an awful lot of time and effort by the trustees of the Greatworth Community Transport Association to achieve what we have. I must say we are all delighted because this is a project by people of Greatworth for the people of Greatworth."