Tokomaru is a small town in the district of Horowhenua, in the southwestern North Island of New Zealand. It is located 18 kilometres southwest of Palmerston North, and a similar distance northeast of Shannon. The Tokomaru railway station on the North Island Main Trunk was open from 1885 to 1982. The Tokomaru Steam Engine Museum features a collection of antique steam engine machinery, much of which is still operational.