The number of volunteers at Kingston Hospital will nearly double by 2016, bosses have said.
Patients with dementia will be the biggest winners as the hospital receives a share of a £600,000 Cabinet Office fund.
Duncan Burton, director of nursing and patient experience, said: "It means that we can grow the scope and impact of our volunteering service, and enables us to provide additional volunteers where the need is greatest.
"One of these areas is for patients with dementia, where trained volunteers will enhance the service we provide, by for example supporting calming activities for patients such as knitting, music and reminiscence therapy."
A new service helping patients when they are discharged will also be launched, he said.
The hospital already has more than 600 volunteers.
To find out how to get involved, contact email@example.com or call 020 8934 3620.