Updated project metadata. Lysine crotonylation of histone proteins is a recently-identified post-translational modification with multiple cellular functions. However, lysine crotonylation of non-histone proteins in fruit cells has not yet been studied. Using high-resolution LC-MS/MS coupled with highly sensitive immune-affinity antibody analysis, a global crotonylation proteome analysis of papaya (Carica papaya L.) fruit was performed. In total, 2,120 proteins with 5,995 lysine crotonylation sites were discovered, among which eight conserved motifs were identified. Bioinformatic analysis linked crotonylated proteins to multiple metabolic pathways, including biosynthesis of antibiotics, carbon metabolism, biosynthesis of amino acids, and glycolysis. Notably, 40 crotonylated enzymes involved in various amino acid metabolism pathways were identified, suggesting a potential conserved function for crotonylation in the regulation of amino acid metabolism. Numerous crotonylation sites were identified in proteins involved in hormone signaling and cell wall-related pathways, indicating a role for crotonylation in the regulation of fruit ripening in papaya. Our comprehensive crotonylation proteome indicates diverse functions for lysine crotonylation in fruit ripening-related proteins.