The Madeira and Porto Santo Islands have both witnessed substantial habitat loss since their initial colonization. Despite their small size and the degradation of their natural habitats, they harbor a rich diversity of terrestrial invertebrates, including a significant number of endemic species. While research on Orthoptera fauna has predominantly focused on the largest island of Madeira, the smaller island of Porto Santo has remained relatively understudied. Fieldwork on both islands has led to the discovery of Oecanthus dulcisonans Gorochov, 1993 in the Madeira archipelago (Porto Santo and Madeira) for the first time. This species was described based on specimens collected in Tenerife and the Arabian Peninsula. However, its distribution, which includes parts of Africa, Western Asia, and some localities in Southern Europe, remains poorly understood. Oecanthus dulcisonans is morphologically very similar to Oecanthus pellucens (Scopoli, 1763), the only species of this genus previously recorded for the island of Madeira. Due to this resemblance, doubts have arisen regarding which of these two species is present in Madeira. By examining new material of O. pellucens, we have confirmed the presence of this species on Madeira as well. These new findings highlight the fact that, for these species, the Madeira archipelago represents the western limit of their distributional ranges in the Palearctic region.