The centre, based in the Glass Works, will help alleviate pressure on existing NHS facilities and will be open seven days a week.
It is seen as a more convenient way for patients to receive ultrasound, X-ray, breast screening, phlebotomy and bone density scans due to its location.
NHS bosses say the clinic will help tackle the backlog created during the Covid-19 pandemic.
Barnsley Hospital’s deputy chief executive, Bob Kirton, said: “We’re delighted to be able to offer vital diagnostic services to our communities in Barnsley and beyond at such a convenient location.
“The Glass Works is perfect for our patients and will mean people will not have to spend so much time travelling to and from the hospital for these important appointments.”
The funding for the diagnostics centre was won by South Yorkshire and Bassetlaw Integrated Care System (SYBICS), who secured £3m for two initial sites in South Yorkshire - the Glass Works and Montagu Hospital in Mexborough.
Local GPs will also be able to refer their patients to the clinic so their patients can access tests closer to home.
Sir Steve Houghton, leader of Barnsley Council, added: “The Glass Works is a superb location for the new diagnostic clinic.
“Its convenient, central location will make it easier for Barnsley residents to get health scans more efficiently and will help reduce NHS waiting lists and improve overall care.”
Screening appointments had been slashed in the early stages of the pandemic - leading to local MPs to urge the government to do more to cope with demand.
Barnsley, once one of the worst-hit places in the country due to its enormous backlog, has turned its fortunes around according to Stephanie Peacock, who represents the Barnsley East constituency.
She told the Chronicle: “More than half of women diagnosed are under the age of 45 and according to Cancer Research UK, 99.8 per cent of all cases can be prevented.
“It’s one of the few cancers that can be prevented through screenings, which only have to take place every three to five years.
“The impact of the pandemic, redirecting much of our health service capacity to deal with Covid-19 - and making access to GPs more difficult - has created further hurdles.
“But our local NHS have been doing some incredible work to deliver vital cervical cancer screening.
“Over the last few months, Barnsley has been one of the top-performing areas in the country for delivering screenings.
“I want to encourage everyone who has not yet been for a screening, who may benefit from one, to make an appointment.”