Insects as an alternative protein source has gained traction for its advantageous environmental impact. Despite being part of many traditional food cultures, insects remain a novelty in Western cultures and a challenging concept for many. Even though plant-based protein alternatives are not facing the same barriers, product unfamiliarity and limited exposure hinder adoption, which could be detrimental to growth within the food sector. This study is aimed at evaluating plant- and insect-based proteins as alternative dietary proteins. A model indicating the drivers of consumer attitudes towards meat-alternative proteins and consumer willingness to try, buy, and pay a premium was tested. Further, 3091 responses were collected using surveys in nine countries: China, USA, France, UK, New Zealand, Netherlands, Brazil, Spain, and the Dominican Republic. Structural Equation Modelling was used to analyze the data. We found that consumer’s behavioral intentions towards both plant-based and insect-based alternatives are inhibited by food neophobia but to an extent, are amplified by the perceived suitability and benefits of the protein, which in turn are driven by nutritional importance, environmental impact, healthiness, and sensory attributes for both alternatives. The expectation of the nutritional value of meat is the strongest (negative) influence on perceived suitability/benefits of plant-based protein and willingness to try, buy, and pay more for plant-based proteins, but it only has a relatively small impact on the suitability/benefits of insect-based protein and no impact on willingness to try, buy, and pay more for insect-based proteins. Overall, we conclude that consumer adoption towards meat alternatives is complex and is strengthened by the perceived suitability/benefits of the protein and general importance of perceived food healthiness and sustainability. Conversely, adoption is hindered by dietary factors and the experiential importance of meat and food neophobia.