The Oscar-winning actor gave the donation to Swansea NHS Trust for patients at the Breast Care Centre at Singleton Hospital, reports the BBC.
Newman had a special reason for helping the hospital. His in-law Sue Proctor, from Swansea, was earlier treated for breast cancer at the centre.
'The Colour of Money' star's daughter Nell is married to Mrs Proctor's son, Gary Irving.
Mike Chare, consultant surgeon at the Breast Cancer Centre commented that the big donation would enhance their service and endorse the work of their staff.
"Not only is this a huge financial boost for our service but a significant endorsement of the work of all our staff," he said.