Background: Over the past decades, advancements in oncological treatments have led to major improvements in survival. Particularly for adolescents and young adults (AYAs), fertility is an important concern in cancer survivorship. The purpose of the review is to provide physicians with a practical overview of the current knowledge about the impact of systemic oncological treatments on the fertility of female and male AYAs. Methods: A systematic review was performed based on relevant articles obtained from 4 databases up until 31 December 2022. Results: The mechanisms of gonadotoxicity and the concurrent risk is described for the following categories: chemotherapy, targeted therapy and immunotherapy. For the category “chemotherapy”, the specific effects and risks are listed for the different classes and individual chemotherapeutics. In the category “targeted therapy”, a distinction was made between tyrosine kinase inhibitors (TKIs) and monoclonal antibodies. Information concerning immunotherapy is scarce. Conclusions: The effects of chemotherapy on fertility are well investigated, but even in this category, results can be conflicting. Insufficient data are available on the fertility effects of targeted therapy and immunotherapy to draw definitive conclusions. More research is needed for these therapies and their evolving role in treating cancers in AYAs. It would be useful to include fertility endpoints in clinical trials that evaluate new and existing oncological treatments.