The Mayor of Lambeth was the guest of honour at the official re-opening of the refurbished Sainsbury's Local store in Waterloo Road on Monday.
The refurbishment of the store includes improved decor and lighting.
The checkout area has also been redesigned with more self-service tills and fewer staffed cash registers.
Cllr Donatus Anyanwu, Mayor of Lambeth, was joined by 15 pupils from Oasis Academy Johanna for the official ribbon-cutting ceremony on Monday.
Store manager Tunc Adsoy said: "We are so excited about opening our refreshed store and getting back to serving our loyal customers who will have missed us this last week.
"Our refit has been long awaited but the result is fantastic with some great new additions."
Staff member Margriet Berndt added: "It is really exciting to have brand new equipment and facilities and a relaxing and upgraded colleague area.
"The refit was so much needed – I am sure it will drive sales and also improve the working environment of my store."
The store – opposite Waterloo Station – is open 24 hours a day.