Amelia Suarez, who founded and ran the Cafe Nova Interchange social enterprise at Elephant & Castle Shopping Centre, is retiring to Spain.
Simon Hughes MP was among the well-wishers at her farewell event.
"The Elephant will simply not be the same without Amelia," says Simon Hughes MP.
"She is a fantastic member of our local community and I have always been really impressed with how hard working and determined she is.
"Cafe Nova Interchange has been the venue for many of my advice surgeries over the years and local residents and I have always been most warmly welcomed.
"The community and I will miss her greatly and I wish her the happiest possible retirement."
Madrid-born Amelia, a former catering manager at St Thomas' Hospital, started the business in 1997 as a training scheme for people with learning and physical disabilities.
Since 2001 the business has traded from the first floor of the Elephant & Castle Shopping Centre, and after a recent refit now has a smarter look and feel.