Precast concrete sandwich panels, consisting of two concrete wythes and a thermal insulation layer in between, have great potential in use for prefabricated building construction. In the present study, experimental and theoretical investigations were conducted to understand the eccentric axial compression behavior of a novel precast concrete sandwich wall panel (SWP), which are made of basalt fiber reinforced polymer (FRP)-reinforced geopolymer concrete for its two wythes and laterally connected with hollow Glass FRP (GFRP) tubular connectors. Nine such SWPs were prefabricated and tested, of which the six were subjected to eccentric axial loading, while the remaining three were tested for concentric axial loading. The primary test variables included slenderness ratio of the SWP, load eccentricity and type of longitudinal reinforcement (FRP bar or grid) in wythes. The load-deflection relationships, failure modes, and load-strain relationships were carefully investigated. It is found that the slender SWPs subjected to large load eccentricity underwent stability failure. The remaining slender SWPs with small load eccentricity and all squat SWPs failed by crushing of concrete (i.e., material failure). The experimental axial load-moment interaction curves were obtained both for the squat and slender SWPs. The second-order moments were found to be 17% and 59% at average of the first-order moments for squat and slender SWPs, respectively. The basalt FRP grids could sustain large tensile and compressive strains without rupturing and local buckling until failure of the SWP. A second-order theoretical analysis was also performed to predict the axial load-moment interaction curves of equivalently assumed solid wall panels, and the predicted results were compared with the experimental ones to validate the modeling.