The data presented in this article are related to the research article entitled “A modelling approach to explore the critical environmental parameters influencing the growth and establishment of the invasive seaweed Undaria pinnatifida in Europe” [1]. This article describes raw simulation data output from a novel individual-based model of the invasive kelp species Undaria pinnatifida. It also includes field data of monthly abundance and recruitment values for a population of invasive U. pinnatifida (in Brest harbour, France) that were used to validate the model. The raw model output and field data are made publically available in order to enable critical analysis of the model predictions and to inform future modelling efforts of the study species.