Stuart Howe, 45, of Woodlands Road, was chosen for the vacancy ahead of Adam Negis, of Elm Court.
Mr Howe has lived in the village for about three years with his wife Stacey, 10-year-old son Noah and the family’s Spanish waterdog Eric.
He said: “Sonning Common has been brilliant for me and my family and I want to give something back to the community.”
Mr Howe, who works for network equipment manufacturer Network Critical in Caversham, has been involved with fundraising for the village scout group and Rotherfield United Football Club, where his son plays.
Two vacancies on the council were created when Colin Reynolds and David Richens stood down in May. The other one was filled by Anthony I’Anson, of Horsepond Road, in July.