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Constant rate-of-strain consolidation, nuclear magnetic resonance transverse relaxation time distribution, mercury injection capillary pressure, grain size distribution, and nitrogen adsorption microporosity measurements were performed on 13 whole-round core samples from International Ocean Discovery Program (IODP) Expedition 372/375 along the Hikurangi margin offshore New Zealand. In this report, whole-round core samples were analyzed from three different sites along the Hikurangi margin subduction zone: Sites U1517 and U1519 on the upper slope and Site U1518 near the Hikurangi Trench. All samples were composed of mostly silty clay to clayey silt sediments. Measurements were used to constrain in situ permeability, porosity, pore size distribution, and consolidation characteristics. Across seven samples from Site U1517, in situ permeability of clayey silts ranged 3.0 × 10−17 to 1.5 × 10−15 m2 and median pore sizes ranged 180–246 nm. A transition from overconsolidated to underconsolidated sediments as expressed by the overconsolidation ratio was identified between 50 and 73 meters below seafloor that aligned with the observed base of the Tuaheni Landslide Complex. Across samples at Site U1518, in situ permeability of silty clays ranged 3.7 × 10−16 to 5.5 × 10−15 m2 and median pore sizes ranged 140–320 nm. Across samples at Site U1519, permeability of silty clays ranged 6.4 × 10−16 to 6.0 × 10−14 m2 and median pore sizes ranged 187–300 nm.