One hundred and twenty-six fish of eight species, taken from Lake Sasajewun, Ontario, were examined for protozoan parasites. Detailed descriptions are given for Sphaerospora diminuta Li and Desser from the pumpkinseed, Lepomis gibbosus, and for Goussia degiustii Molnar and Fernando from the common shiner, Notropis cornutus. Oocysts of G. degiustii are pleomorphic and exhibit low tissue specificity. Goussia freemani Molnar and Fernando from the kidney of N. cornutus is tentatively synonymized with Goussia leucisci Shulman and Zaika. Two new species of Sphaerospora are described: Sphaerospora paulini n.sp. from the renal tubules of creek chub, Semotilus atromaculatus, with spherical spores 8.1 (8.0–8.5) μm in diameter, containing ovoid polar capsules 2.8 (2.5–3.4) × 2.6 (2.5–3.0) μm, and polar filament with 4–5 coils; and Sphaerospora hankai n.sp. from the renal tubules of the brown bullhead, Ictalurus nebulosus, with subspherical spores 6.1 (5.4–6.6) × 6.0 (5.4–6.5) μm, unequal subspherical polar capsules (larger, 2.8 (2.5–3.1) × 2.7 (2.3–2.9) μm; smaller, 2.4 (2.1–2.6) × 2.0 (1.9–2.2) μm), and polar filament with 4–5 coils in larger capsule, 3–4 coils in smaller capsule. Eimeria patersoni n.sp. is described from the kidney, spleen, and liver of L. gibbosus. Oocysts are subspherical (11.9 × 10.6), sporocysts ellipsoidal (10.4 (9.9–11.2) × 3.5 (2.6–4.0) μm), and sporozoites stubby (3.6 × 2.0 μm); sporocyst residuum has 1–3 large granules.