BackgroundPediatric food allergy is associated with excess familial food costs compared to families without allergy. Since the start of the COVID-19 pandemic, food prices have increased substantially.ObjectiveTo understand the temporal pattern of food insecurity amongst Canadian families with food allergy from the year prior to the pandemic, through May 2022.MethodsUsing data collected electronically from families reporting food allergy using a validated food security questionnaire, we estimated food insecurity, including categories of food insecurity (marginal, moderate, secure) in the year prior to the pandemic (2019; Wave 1), and the first (2020; Wave 2) and second years of the pandemic (2022; Wave 3).ResultsParticipants in all waves were commonly in 2 + adult, 2 child households. Less than half of participants (Waves 1–3: 45.7%, 31.0%, and 22.9%, respectively) reported household incomes below the median Canadian. Common allergies were milk, eggs, peanuts and tree nuts. In Wave 1, 22.9% of families reported food insecurity; corresponding numbers at Waves 2 and 3 were 30.6% and 74.4%, respectively, representing an overall increase of 225.6%, including notable increases in severe food insecurity.ConclusionCanadian families with pediatric food allergy report higher rates of food insecurity compared to the general Canadian population, especially during the pandemic.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13223-023-00802-6.