The pub, based in Carshalton Road, beat 27 others for the title in a competition organised by Paul Scully, prospective conservative MP of Sutton and Cheam.
More than 1,500 customers voted online with The Robin Hood and Gander Inn coming second and third.
Paul Scully said: "This competition has been really enjoyable to organise. The willingness with which customers participated shows how much residents cherish their local as a community hub.
"The Nightingale is a great example of a pub that draws in both local regulars and people from a good distance away, all of whom like good company, good music and a decent drink."
- Commuters face travel chaos as Southern Rail cancels more than 1,000 services due to strike
- Man rushed to hospital following attack in Sutton High Street
- Network Rail reportedly set to lose sole control of British rail infrastructure
- London Mayor Sadiq Khan to spend 'record amount' on London cycling initiatives
- Bless this public house: Reverend sprinkles holy water on pumps in quirky annual tradition