The chemical investigation and in vitro cytotoxic, caspase and apoptotic activities of extracts/n-hexane fractions of eleven diverse marine organisms, collected from the Red Sea at the Egyptian coasts, were studied against the human hepatocarcinoma (HepG2). The organisms were identified as Thalassia hemprichii [SP1], Sargassum arnaudianum [SP2], Echinodictyum flabelliforme [SP3], Dendronephthya hemprichi [SP4], Rumphella sp. [SP5], Iotrochota purpurea [SP6], un-identified [SP7], Sarcophyton glaucum [SP8] and Sarcophyton sp. [SP9]), Ircinia sp. [SP10] and Ircinia echinate [SP11]). Phytochemical profiling by GC-MS analysis of the hexane components obtained from the eleven organisms revealed their unique diversities, reporting altogether 114 divers compounds. According to anticancer profiling the n-hexane fractions of the reported organisms showed diverse potent cytotoxicity against HepG2: the soft coral Dendronephthya hemprichi [SP4] showed cytotoxic activity at IC50 = 25 and 12.5 µg/mL after 24 and 48 h, respectively, meanwhile the sponge [SP6] showed less cytotoxicity of IC50 = 100 and 50 µg/mL after 24 and 48 h, respectively), accompanied with moderate induction of non-apoptotic caspase-activity. The unidentified soft coral [SP7] had time-independent cytotoxicity (IC50= 20 µg/mL) after 24 and 48 h, accompanied with high-induction of caspase–dependent early apoptosis. Sarcophyton glaucum [SP8] was potentially cytotoxic (IC50= 12.5 µg/ml after 24) without induction of caspase-activity or apoptosis, meanwhile the soft coral [SP9] showed induction of caspase–independent apoptosis. Finally, the brown alga [SP2] showed high induction of non-apoptotic caspase-activity after 48 h. This recognized the high potentiality of the marine organisms, [SP2], [SP4], [SP7], [SP8] and [SP9] as talented sources of drug leads with significant biological activities, encouraging our future research planning to isolate and structurally identify such corresponding potentially active compounds.