Fresh basalts from the Ontong Java Plateau (OJP) and the Shatsky Rise show lithium enrichments comparable to those of mid-oceanic ridge basalts (MORBs) and ocean island basalts (OIBs), with Li contents being significantly higher at a given MgO content. The Li isotopic compositions of the Shatsky Rise basalts (δ⁷Li = +6‰ to +7‰) are at the higher end of the range exhibited by OIBs, whereas OJP basalts (δ⁷Li = +3‰ to +5‰) have Li isotopic compositions similar to MORBs. Among all the basalts from the two oceanic large igneous provinces (LIPs), one sample from the Shatsky Rise is isotopically enriched (e.g., low ¹⁴³Nd/¹⁴⁴Nd and ¹⁷⁶Hf/¹⁷⁷Hf) and has higher K/Ti and lower La/Nb than the other samples. Relationships between δ⁷Li and K/Ti, La/Nb, and Rb/Nb of this sample indicate that it may have been affected by mantle that was metasomatized by slab-derived fluids. Apart from this isotopically enriched sample, δ⁷Li values of basalts from the two oceanic LIPs are positively correlated with K/Ti and Rb/Nb. Obvious linear relationships exist between δ⁷Li and Yb/Li, Y/Li, and Dy/Li for samples from the Shatsky Rise. These geochemical relationships can be explained by magmatic assimilation of hydrothermally influenced crust. The high δ⁷Li values of the Shatsky Rise basalts imply that the degree of assimilation is high because shallow magma chambers allow greater assimilation of hydrothermally influenced crust. In contrast, the low δ⁷Li values of the OJP samples may indicate they have undergone little assimilation as compared with the Shatsky Rise basalts.