Dust in galaxies refers to the presence of small solid particles, typically composed of carbon, silicates, and other elements, in the interstellar medium of galaxies. This dust plays a crucial role in the formation and evolution of galaxies, as it absorbs, scatters, and re-emits radiation at various wavelengths, affecting the observed properties of galaxies. Studying dust in galaxies involves understanding its distribution, composition, and physical properties, as well as its impact on star formation, galaxy evolution, and the overall energy balance in galaxies. Observations of dust in galaxies are often conducted using infrared and submillimeter telescopes, as dust emits strongly at these wavelengths. Overall, research on dust in galaxies provides important insights into the complex interplay between the gas, stars, and dust in galaxies, and how these components shape the observable properties of galaxies across cosmic time.