Phytochemical investigation of the methanolic extract of Tagetes minuta L. (Asteraceae) leaves resulted in the isolation and identification of two new compounds: 5-methyl-2,2',5',2'',5'',2''',5''',2''''-quinquethiophene (1) and quercetagetin-6-O-(6-O-caffeoyl--D-glucopyranoside) (9), in addition to seven known compounds: quercetin-3,6-dimethyl ether (2), quercetin-3-methyl ether (3), quercetin (4), axillarin-7-O--D-glucopyranoside (5), quercetagetin-3,7-dimethoxy-6-O--D-glucopyranoside (6), quercetagetin-7-methoxy-6-O--D-glucopyranoside (7), and quercetagetin-6-O--D-glucopyranoside (8). The compounds were identified by UV, IR, 1D, 2D NMR, and HRESIMS spectral data. They showed significant antioxidant activity, comparable with that of propyl gallate. Compounds 8 and 3 showed weak to moderate antileishmanial and antimalarial activities, with IC50 values of 31.0 μg/mL and 4.37 μg/mL, respectively.