Fog is a natural meteorological phenomenon that severely reduces atmospheric visibility and adversely affects air and ground transportation systems, leading to disruptions, delays, and increased accident risks. Cities, due to their nature as concentrated hubs of people, infrastructure, and technology, are more vulnerable to the economic losses due to fog occurrence. Urbanization introduces a myriad of factors unique to every city—morphology of buildings, blue-green infrastructure, anthropogenic heat, wind tunnels, etc.—that can intensify or suppress fog formation by altering the radiation, moisture, and wind dynamics. The urban ecosystem not only contributes to changes in urban fog frequency and density but also influences its behavior, persistence, structure, duration, and location within cities. Additionally, anthropogenic forcings, including higher air pollutant and aerosol concentrations in cities compared to rural regions, create a distinctive and more complex chemical form of urban fog, which poses significant public health risks. Large-scale forcings further amplify the local effects of urbanization on fog dynamics, presenting a serious challenge toward predicting the spatiotemporal extent and visibility degradation of urban fog. This chapter highlights the different facets of urbanization, the feedback mechanisms through which it modifies the local weather and climate of cities, and how it modulates the urban fog dynamics.