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A series of oligomeric phenols including the known natural product 3,4,3′,4′-tetrahydroxy-1,1′-biphenyl (3), the previously synthesized 2,3,8,9-tetrahydroxybenzo[c]chromen-6-one (4), and eight new related natural products, cladophorols B–I (5–12), were isolated from the Fijian green alga Cladophora socialis and identified by a combination of NMR spectroscopy, mass spectrometric analysis, and computational modeling using DFT calculations. J-resolved spectroscopy and line width reduction by picric acid addition aided in resolving the heavily overlapped aromatic signals. A panel of Gram-positive and Gram-negative pathogens used to evaluate pharmacological potential led to the determination that cladophorol C (6) exhibits potent antibiotic activity selective toward methicillin-resistant Staphylococcus aureus (MRSA) with an MIC of 1.4 μg/mL. Cladophorols B (5) and D–H (7–11) had more modest but also …