Abstract: The present invention provides: a highly practical and safe oil-based ink composition for a writing board, said composition being capable of imparting high mark-erasability and having excellent resistance to drying up; and a marking pen incorporating the same. Specifically, the present invention provides: an oil-based ink composition for a writing board, said composition containing a pigment, an organic solvent, a resin, and at least one compound selected from compounds represented by general formula (1) or (2); and a marking pen obtained by incorporating the oil-based ink composition for a writing board. (In the formulae, R1-R4 each represent a C6-18 alkyl group or a C2-18 and O2-10 alkoxypolyglycol group.