The pharmacological screening of some crude extracts obtained from different marine algae collected from the Mediterranean in Alexandria region in Egypt has been conducted. The methanol, butanol, and ethyl acetate extracts of Pterocladia capillacea, Ulva lactuca and Corallina mediterranea showed inhibitory activity against the growth of Lemna minor plant. The methanol and petroleum ether extracts of Ulva lactuca (VII) exhibited significant antioxidant activity 92.2 and 84.6%, respectively, in the DPPH free radical scavenging assay. The methanol and ethyl acetate extracts of Pterocladia capillacea and Corallina mediterranea showed remarkable inhibitory activity against butyrylcholinesterase. The ether extract of Pterocladia capillacea (III) and the petroleum ether extract of Ulva lactuca (VII) exhibited high antiglycation activity (69.4% and 65% with IC₅₀ of 0.0596 ± 0.0447 mM and 0.138 ± 0.0441 mM, respectively). The ether extract of Ulva fasciata (I) potently inhibited the oxidative burst activity of phagocytes from whole blood analysis (97.99%) at a concentration of 400 µg/mL.  Scanning by electron microscope (SEM) showed successful encapsulation of the bioactive algal extracts into calcium alginate beads. Tested marine macroalgae have the potential to produce bioactive metabolites with significant antifungal, phytotoxic, antioxidant, anticholinesterase, antiglycation, and immunomodulating activities.