Groundwater occurrence in crystalline basement complex is mainly due to the development of secondary porosity and permeability arising from the weathering and fracturing of the low porosity igneous and metamorphic basement rocks. In this study, geophysical survey involving seismic refraction and 2D electrical resistivity tomography (ERT) was conducted to assess the hydrogeological characteristics of the weathering profile of the crystalline basement rocks in Olomore, Abeokuta, southwestern Nigeria. The 2D ERT survey was conducted along five Traverses using dipole-dipole array with a minimum electrode spacing of 5.0 m in Traverses 1, 2, 3 and 5, and 10.0 m in Traverse 4, and a dipole separation factor of 1 – 4 in all the traverses; the observed apparent resistivity data were inverted using RES2DINV. The seismic refraction survey was conducted along the same traverses using 10 Hz electromagnetic geophones; the refraction data were processed using SeisImager with the first arrival travel times picked using Pickwin module and inverted using Plotrefa to obtain velocity model of the subsurface. A good correlation exists between the 2D ERT images and the seismic refraction velocity models. The effective depth of investigation for both ERT and seismic refraction is approximately 43.0 m in all the traverses except for ERT of Traverse 4 which 66.0 m depth of investigation. Four lithologic layers may be inferred with varying model resistivity and P-wave velocity range of 546-974 m/s, 1456-1877 m/s, 2042-2944 m/s, and 3041-6894 m/s respectively. Both ERT and seismic refraction images indicate that the regolith (collapsed zone and saprolite) is relatively thin (< 10.0 m) and may be unable to support adequate drawdown for good yield. But the weathered and fractured basement is sufficiently thick to support adequate drawdown for high groundwater storativity and yield; depth-to-bedrock is greater than 20.0 m in most part of the study area. The study shows that the combination of ERT and seismic refraction is effective for near-surface characterisation for hydrogeological investigations in crystalline basement complex.