ABSTRACT Evolutionary theory is considered the unifying theory of modern biosciences, but the public continues to misperceive the prevailing scientific consensus. Science communication studies emphasise the influence of perceived scientific and social consensus on personal beliefs, which can be manipulated through communication strategies. This study investigates the impact of consensus messaging on (1) perceptions of scientific and social consensus, (2) students’ feelings of certainty about these perceptions, and (3) acceptance of evolutionary theory. Employing a 2 × 2 factorial design (Factor 1: scientific consensus messaging versus consensus uncertainty; Factor 2: social consensus messaging), we randomly assigned 218 German upper secondary school students to one of four text variants to complete a close-ended pre – post questionnaire. We found positive correlations of evolutionary theory acceptance with perceived scientific and social consensus, and with feeling of certainty regarding perceived scientific consensus. Scientific consensus messaging positively affected perceived scientific consensus and feeling of certainty. Assessed with all items of MATE 2.0, acceptance decreased in the consensus uncertainty condition. When measured with two items, acceptance increased with scientific consensus messaging. The role of consensus messaging in teaching evolution and its use as a component of teaching strategies in evolutionary education and other fields are discussed.