Scolomus Townes & Townes, 1950 is a genus in Ichneumonidae, with six species occurring in the Holarctic and Neotropical regions. In this study, a new species is described from Chile, Scolomus valenzuelai Araujo, Pádua & Silva-Santos, sp. nov. Also, the female of S. magellanicus Walkley, 1962 is described for the first time and new occurrences of S. maculatus Araujo & Vivallo, 2018, and S. magellanicus are reported from Chile, including the northernmost record of this genus in South America. Additionally, we provide an updated identification key for all known species of the genus.