Thanks to their various promising properties, bioactive peptides extracted from microalgae have recently attracted great attention from scientists. These compounds have been mostly obtained by enzymatic hydrolysis. In the present study, proteins from the marine microalga Rhodomonas sp. were hydrolysated into peptides using alcalase and pepsin. After obtaining the peptides, we characterized them and the crude protein by Fourier-transform infrared spectroscopy. Then, the biological activities of all protein preparations were evaluated. Antioxidant activity was investigated using DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical-scavenging and ferric reducing power assays. The obtained results showed that crude protein presents higher antioxidant activity (74% at 1 mg/mL) compared to peptides obtained after hydrolysis by pepsin (56.5% at 1 mg/mL) and alcalase (47.5% at 1 mg/mL). The anti-inflammatory activity was also evaluated by inhibition of the denaturation of albumin assay. An interesting anti-inflammatory activity was obtained using protein extract. It was improved after enzymatic hydrolysis using pepsin to reach 89% of inhibition at 500 µg/mL. The obtained data showed that the marine microalga Rhodomonas sp. could be a potential source of valuable proteins and peptides for the pharmaceutical and cosmetic fields.