The new deal, worth an estimated £536,719 for the first three years, includes an option to renew for a further two years.
Cucina's managing director Steve Quinn said: "Southfield School was our first ever contract and our relationship with the school has gone from strength to strength.
“I am thrilled to be continuing this partnership."
Southfield School, with 1,030 girls aged 11-18 on roll, has Sports College and Science specialisms and became a centre for Gifted and Talented students in 2009.
Headteacher Julie Goswell said: "We were delighted to be able to renew the contract with Cucina for a further five years.
“Cucina has run the restaurant in Southfield School since 2006 and it has provided us with an excellent service. The menu is varied and there is always a choice of healthy, wholesome and nutritious food.
“Cucina staff are professional and courteous at all times, treating school staff and pupils as valued customers. I have not eaten food in any other school canteen that can equal that offered by Cucina."