Abstract: This study investigates the types of humor embedded in funny scientific posts on social media and their effects on engagement. We mapped the landscape of such posts on Twitter and Instagram through content analysis of their message attributes. Regression analyses were then conducted to examine how different humor types, communicative functions, and visual attributes were associated with liking, retweeting, and commenting. On Twitter, wordplay and satire were found to be positively related to posts’ engagement levels, while anthropomorphic humor was negatively associated with the presence of comments. On Instagram, humor had no relation to engagement.