Abstract There is a pressing need for healthy diets guided by environmental and nutritional targets. Plant‐based proteins have emerged as a recent and rapidly growing trend in response to the challenge of sustainable and healthy food systems. While plant‐based protein foods are widely promoted as sustainable alternatives, shifting beliefs and attitudes about conventional protein sources present an ongoing challenge. The study examined Canadians' intentions to transition to plant‐based protein diets, partially or entirely. A nationally representative survey was conducted among Canadian consumers to achieve our research objective. The survey was administered online using the Qualtrics platform by a market research firm and yielded valid responses from over 1800 participants. The Theory of Planned Behavior (TPB) constructs—attitudes, self‐efficacy, and perceived availability—explained only 12% of the variation in intentions toward plant‐based protein foods, while sustainability and ethical concerns accounted for 10% of the variation in dietary patterns. Meat attachment negatively impacted changes in dietary patterns, explaining 11% of the intention variation. Additionally, individual past behavior accounted for 7% of intentions toward plant‐based proteins. Demographic factors, such as gender and education, strongly and positively predicted purchase intentions, while contextual factors, such as residing in rural neighborhoods and being from Atlantic Canada, showed a strong negative association with intentions toward plant‐based protein diets. The findings underscore the multifaceted nature of individuals' intentions toward plant‐based protein diets and emphasize the significance of considering cognitive, social, emotional, and past behavioral factors, alongside sustainability values and messaging, to transition to a more plant‐based protein diet. This approach should carefully balance individuals' emotional connection and the perception of meat as essential to their meals. Also, targeting interventions based on demographic characteristics, specifically gender, education, and residential neighborhood, can enhance changes in dietary protein sources. The findings contribute to the existing body of knowledge on consumer behavior and sustainable diets, guiding future research and policies informing the design of effective interventions to promote plant‐based protein consumption and dietary changes.