Tropical dry forests (TDFs) are unique ecosystems with high biodiversity, including a rich variety of lichen species. Lichens are sensitive to environmental changes and can serve as bioindicators of ecosystem health. This study examined the diversity of lichen communities at four TDF sites in the Atlántico Department of Colombia. More than 700 tree lichen specimens were collected and identified at the four sites. A total of 135 species of lichens were identified, of which 19 are possibly undescribed. The most diverse sites were Usiacurí and Repelón, both protected areas with relatively well-preserved forests. The findings of this study demonstrate that the Atlántico TDFs host a large diversity of lichens, with a significant number of records of new species. The observed differences in species composition between sites highlight the importance of habitat heterogeneity and anthropogenic pressures on lichen communities. The results emphasize the need for conservation strategies to protect these ecologically valuable lichen communities within the Atlántico TDFs.