Formaldehyde (FA) is an oxidative stress inducer and a known carcinogen. Hedeoma drummondii has been shown to have potential as a chemopreventive agent. The aim of this study was to assess the protective effect of H. drummondii on FA-induced genotoxic damage, sperm quality parameters, and histological changes of the testis. The male Wistar rats used were divided into the following groups: (G1) 100 mg/kg H. drummondii; (G2) 10 mg/kg FA; (G3) 100 mg/kg H. drummondii + 10 mg/kg FA; (G4) phosphate-buffered saline; (G5) 100 mg/kg α-tocopherol; (G6) 100 mg/kg α-tocopherol + 10 mg/kg FA; and (G7) soybean oil. The results showed a sperm concentration of 23.66 ± 1.52 versus 33.67 cells/mL (
p
=
0.02
), and a percentage of motility of 29.66 ± 1.51 versus 33.33 (
p
=
0.620
), for groups G3 and G6, respectively. Histopathological (H&E) and immunohistochemical analysis of superoxide dismutase showed damage in the germinal epithelium (GE) in G2. While in groups G3 and G6, the histological structure was preserved. A protective effect on sperm DNA fragmentation was also observed for treated groups (G3 and G6,
p
<
0.0001
vs. G2). While in groups G3 and G6 the histological structure was preserved. A protective effect on sperm DNA fragmentation was also observed for treated groups (G3 and G6). In conclusion, FA exposure significantly reduces sperm quality parameters, causes sperm DNA damage, and alters GE in the testis, while H. drummondii has a protective effect against FA-induced sperm genotoxic damage, similar to α-tocopherol.