The deal, at the superstore in Broadpiece, runs until Wednesday, September 1.
It covers the Pick “N” Mix meal deal, usually £2.75, which includes a sandwich, soft drink, piece of fruit and two snacks, or a kids’ hot meal, such as baked chicken goujons, Omega 3 fish fingers or ‘hidden veg’ Mac and Cheese
There are also kids breakfast options available in the deal, including eggs or avocado, both on toast.
Jo Barnes, head of marketing and food development at Tesco Café, said: “The summer holidays are the perfect opportunity for some quality family time and a little treat.
“Families can enjoy a premium quality breakfast, lunch or dinner together whilst shopping at Tesco, all for great value as kids eat free when an adult spends just £3.50.”
“We’ve worked really hard to ensure we’re offering balanced and healthy options for our little diners.
“We encourage well balanced and healthier kids meal options by adding a vegetable side with every hot meal, a piece of fruit with every cold meal and ensuring all our kids snacks are under 100 calories.
“We strongly believe that eating out shouldn’t have to cost families a lot of money, especially in the expensive summer holidays, and we wanted to provide some unbeatable offers for families.
“We’re really looking forward to welcoming our customers into the café this summer.”