The bus will first stop off in the Blakenhall ward in Wolverhampton, as part of a pilot scheme introduced by the city council and the NHS.
It will remain in Phoenix Park for a number of days before being moved on to a new area of Wolverhampton.
Patients who are deemed eligible for vaccines can turn up for their first dose without needing to book an appointment.
John Denley, director of public health in Wolverhampton, said: "We hope this initiative will speed up vaccination uptake in the city."
The mobile clinic has been rolled out amid the emergence of the Delta variant of Covid-19, formerly known as the Indian variant, in the UK - which is thought to be more contagious than other strains.
To help with the country's ongoing fight against coronavirus, health officials are specifically targeting areas in Wolverhampton with low uptakes.
Volunteers will be knocking on doors within the ward, encouraging people who have not had vaccines to come forward.
Wolverhampton Council leader Ian Brookfield said the goal was to have "95 per cent" of the city's population vaccinated.
Councillor Jasbir Jaspal, cabinet member for public health, added: "I am very excited to have this bus come along and get to our hard-to-reach communities who maybe haven't been able to go to their GP or vaccination centre.
"It is so important to protect our people."
The bus will remain in Blakenhall for five days before health officials will decide whether to move to a new location.
Dr Rajnish Mohindroo, a local GP helping to organise the programme, said there has been lower uptakes in communities from Black And Minority Ethnic [BAME] backgrounds.
It is hoped the easy access to the bus in Blakenhall, being in a park along a busy road, will make it more encouraging for people to get vaccinated, he said.
Asked why Blakenhall had a low vaccine uptake, he said: "This is a national thing, we are trying to find out why certain areas have poorer uptake compared to others.
"Obviously, Phoenix and this area has got a higher BAME population. Maybe, initially, there was some reluctance.
"But I think a lot has changed since what has happened in India."
He continued: "Younger cohorts have been difficult to target too but generally it is just to do with work commitments."
Dr Mohindroo added: "I am really excited for this because, for us, it is a game changer in terms of access.
"This is a five day pilot for us to reflect and understand and see whether we are benefitting from it."
The bus will be open from 11am until 7pm everyday until Sunday evening.