Food allergy affects approximately 1% to 10.8% of the general population, and its prevalence seems to be increasing. An accurate diagnosis is particularly important because a misdiagnosis could lead to life-threatening reactions or to unnecessary restrictive diets. However, allergy tests currently used in clinical practice have limited accuracy, and an oral food challenge, considered as the gold standard, is often required to confirm or exclude a food allergy. This article reviews several promising novel approaches for the diagnosis of food allergy, such as new molecular diagnostic technologies and functional assays, along with their potential clinical applications.