IIASA is, for the very first time, offering a Summer School on Systems Modeling (15-26^th July 2024). The two-week school is designed for Master’s, PhD students and post-doctoral researchers who wish to use or develop models broadly related to the sustainability agenda. The goal is to equip participants with a solid understanding of modeling practices and limitations of models. Many examples will be taken from IIASA’s portfolio of tools and methods, ranging from ecological models, socio-economic systems, to integrated assessment tools of energy, air, water, biodiversity, and food.