The minister thanked staff for their “superhuman efforts” in maintaining services across the Covid pandemic, which has led to unprecedented pressures on hospitals.
Mr Swann made the announcement in a letter to health workers, seen by PA news agency.
It comes on top of a three per cent pay rise which he announced last year.
Staff will receive between 0.5% and 1.5%, with the higher award going to lower paid workers.
It is understood trade unions have been informed of the latest pay award, which will be backdated until April of last year.
Mr Swann’s letter said: “These have been a truly unprecedented two years.
“We have faced challenges and pressures like never before and we have all had to make some incredibly difficult changes and to take deeply uncomfortable decisions.
“Last November, I announced I would be implementing the three per cent 2021-22 pay award that had been recommended by the NHS Pay Review Body.
“Whilst it was obviously better than the 1% increase that was previously speculated, I also said if I could find funding to deliver a greater award I would do so.”
The letter continued: “Having spent the last number of weeks and months exploring what funding I could make available, and after engaging with trade union colleagues, I am very pleased to be able to announce a further in-year pay award for HSC staff.
“In total this additional pay award will represent a further investment of £25m into our healthcare workforce.
“It is utilising funding I have within my department and therefore it is being implemented without additional funding from Treasury for pay.”
Mr Swann added: “Although we are hopefully through the worst of the Omicron wave in terms of case numbers, I am acutely aware that pressures remain immense across our health service.”