This report marks the 51st consecutive annual overview of remarkable records of Macrolepidoptera in Sweden, incorporating a compilation of new provincial records. Most of these records were obtained from personal reports and the Swedish Species Observation System (https://www.artportalen.se). In 2023, 101 new provincial records were registered, including two species of Macrolepidoptera new to Sweden: Cryphia fraudatricula and Caradrina gilva. Noteworthy, rare migrants observed in 2023 include Orthonama obstipata, Xylomoia graminea, Amphipyra livida, Catocala electa, Aedia funesta, Agrotis bigramma, Acherontia atropos and Mythimna vitellina. In response to land use and climate changes, numerous species continue colonising new provinces, expanding their ranges primarily northwards and inland within Sweden. Examples of such species include Apatura iris, Cosmia affinis, Noctua interposita, Cryphia algae, Caradrina kadenii, Hoplodrina ambigua, Mythimna albipuncta, Anorthoa munda and Conisania luteago. Conversely, many species, such as Photedes captiuncula and Athetis pallustris, are experiencing range contractions due to intensified land use and habitat destruction. The report also highlights the absence of observations of the critically endangered butterflies Melitaea britomartis, Plebejusargyrognomon, and the endangered Boloria polaris, raising concerns that these species may now be extinct in Sweden. Additionally, several species associated with taiga forests, such as Baptria tibiale, Victrix umovii, and Xestia collina, are reported to have very few localities, with correspondingly scarce records. The total number of Macrolepidoptera recorded in Sweden has reached 1 134, of which 16 are introduced species.