Rent burden is a situation when a renter‐occupied household spends a sizable portion of its income on housing costs. Using census tracts as the scale of analysis, this article examines rent burden determinants in Shelby and Davidson counties, the two largest of Tennessee. These counties differ substantially in terms of their housing markets, demographics, and the state of their economy. Mapping reveals distinct spatial patterns of rent burden and its geographic extent. Correlations and spatial regression analyses suggest that in both counties, a lack of access to an automobile, crowded living, and the presence of children in households similarly associate with higher rent burden. In contrast, educational attainment, race, and a lack of medical insurance do not demonstrate such consensus. Compared to Davidson County, race is a less crucial predictor of rent burden in Shelby County, likely due to its predominantly African American composition across different income groups. Besides, the positive effect of education is more pronounced in Shelby County. Results indicate that rent burden tends to be more of a socioeconomic class issue in Shelby County, whereas it is not as strongly associated with the socially disadvantaged in Davidson County.