Searches for new phenomena in final states involving leptons and jets using the ATLAS detector

Many beyond the Standard Model signatures predict new physics phenomena that lead to final states containing both leptons and jets. The latest search results for massive particles or lepton flavour violation using the full Run 2 dataset recorded by the ATLAS experiment are presented. A particular focus is given to searches for leptoquarks, that offer an attractive potential explanation for the lepton flavour anomalies observed at $B$-physics factories; searches for heavy leptons, such as the ones appearing in Type-III seesaw model that can explain the smallness of neutrino masses; and lepton flavour violating $Z$ decays, which is an excellent probe for new physics that predict direct lepton flavour violating processes.