As a result of fieldwork in the island of Madeira (Portugal) in the autumn of 2021 and the spring of 2022, nine nonnative grasses are newly reported: Axonopus fissifolius, Chloris pycnothrix, Digitaria radicosa, D. violascens, Eragrostis multicaulis, Nassella hyalina, Paspalum notatum, P. urvillei and Sporobolus aff. fertilis. All are at least locally naturalized in the island of Madeira and, elsewhere in the world, they are often considered invasive species or weeds. In addition, the identity of species from the Hyparrhenia hirta and Setaria verticillata complexes is discussed. Finally, some miscellaneous notes on other noteworthy grasses are also presented.