A portable terminal holding device for a vehicle includes: a table configured to be stored in a storing portion provided at one end side, in a seat width direction, of a seat cushion, and that, in a state of usage, is configured to extend from the storing portion toward another end side, in the seat width direction, of the seat cushion; and a terminal holding portion that, in the state of usage of the table, is provided at a distal end side of the table and is configured to hold a portable terminal, and that, in a stored state in which the table is stored in the storing portion, projects out from the storing portion toward the other end side in the seat width direction.