Tomato (Solanum lycopersicum L.) is a widely cultivated horticultural crop. It is a member of the Solanaceae family and is reknowned for its high concentration of essential nutrients, including vitamins, minerals, and bioactive compounds with antioxidant properties. The Mediterranean countries, including Italy, Spain, and Greece, have a diverse range of tomato landraces. Assessing the nutritional and bioactive composition of different tomato varieties and their ripening stages is crucial to determine their suitability for the market. Thus, this research was aimed to examine the effect of ripening on the nutritional composition (including carotenoids and polyphenols content) and the antioxidant activities of fruits from three specific tomato varieties grown in Spain: Josefina and Karelya, which are cherry-like tomatoes, and Muchamiel, a type of salad tomato. In addition to evaluating their characteristics and composition (including carotenoids and polyphenols content), and assessing the antioxidant activities of these varieties at three different stages of ripening were quantified. As expected, the findings revealed that as the tomatoes matured, their antioxidant capacity increased alongside higher levels of carotenoids and polyphenols. Interestingly, the cherry-like tomatoes showed greater antioxidant activity than the salad tomatoes. This investigation emphasizes the role of fruit ripening in enhancing carotenoid levels, which contribute to the antioxidant activity of three varieties of tomatoes.