This data package describes the annual abundance indices and trend estimates for 22 butterfly species in UK gardens for the period 2007-2020. These data form the basis of the results presented in: Plummer, K.E., Dadam, D., Brereton, T., Dennis, E.B., Massimino, D., Risely, K. et al. (2023) Trends in butterfly populations in UK gardens—New evidence from citizen science monitoring. Insect Conservation and Diversity, 1– 13. Available from: https://doi.org/10.1111/icad.12645 Please refer to the paper for an explanation of the underlying BTO Garden BirdWatch (GBW) data and modelling protocols used to produce the datasets included here. We would also greatly appreciate if you could fill out this very short form to tell us how you intend to use these data. Thanks in advance!