Pat Smith, from Darwen, Lancashire, was clearing the draw out when she found the medal in a "box of interesting objects", brought home by her husband.
She did some research online to track the owner, Sam Hallas, and discovered he lived in South Manchester in 1911.
The Second Boer War took place between 11 October 1899 - 31 May 1902.
The medal has been sent to Manchester and will be transported to Cyprus, where his grandson David Hallas lives.
Mr Hallas did not know his grandfather was awarded a medal in the Second Boer War and said the discovery was a surprise to the whole family.
"It was absolutely fantastic," he said.
"All the trouble Pat went through to trace it was brilliant, I really appreciate what she has done. I could not thank her enough."
Inspired by Mrs Smith's discovery, Mr Hallas is now determined to find out more about his grandfather and his involvement in the Second Boer War.
He is expecting his daughter, who is currently living in Manchester, to post the medal to Cyprus once she receives it.
A woman found a Boer War medal in a drawer in her house which had lain there unbeknown to her for 15 years.