The present invention provides a novel molecule that catalyzes a hydrolysis reaction and is different from enzyme proteins. The catalytic peptide according to the present invention is a catalytic peptide that catalyzes a hydrolysis reaction, including at least one peptide selected from the group consisting of the following peptides (A1) to (A4): (A1) a peptide consisting of Box A and at least one of an upstream region and a downstream region therefrom in a Tob/BTG protein; (A2) a peptide consisting of a partial region of the peptide (A1); (A3) a peptide that consists of an amino acid sequence obtained by deletion, substitution, addition, and/or insertion of one or more amino acids in an amino acid sequence of the peptide (A1) or (A2) and has hydrolysis activity; and (A4) a peptide consisting of an amino acid sequence with a sequence identity of at least 85% to the amino acid sequence of the peptide (A1) or (A2) and having hydrolysis activity.