Routine childhood vaccination is a crucial component of public health in Canada and worldwide. To facilitate catch-up from the global decline in routine vaccination caused by the COVID-19 pandemic, and toward the ongoing pursuit of coverage goals, vaccination programs must understand barriers to vaccine access imposed or exacerbated by the pandemic. We conducted a regionally representative online survey in January 2023 including 2036 Canadian parents with children under the age of 18. We used the COM-B model of behaviour to examine factors influencing vaccination timeliness during the pandemic. We assessed Capability with measures of vaccine understanding and decision difficulty, and Motivation with a measure of vaccine confidence. Opportunity was assessed through parents' self-reported experience with barriers to vaccination. Twenty-four percent of surveyed parents reported having missed or delayed one of their children's scheduled routine vaccinations since the beginning of the pandemic, though most parents reported having either caught up or the intention to catch up soon. In the absence of opportunity barriers, motivation was associated with timely vaccination for children aged 0–4 years (aOR = 1.81, 95 % CI: 1.14–2.84). However, experience with one or more opportunity barriers, particularly clinic closures and difficulties getting an appointment, eliminated this relationship, suggesting perennial and new pandemic-associated barriers are a critical challenge to vaccine coverage goals in Canada.