This article traces trends of income inequality in Mexico City from 1770 to 1930 by measuring the gaps between urban real estate rents and unskilled wages. The article presents the first long‐term series of real estate values and rental income for Mexico. One series summarizes the price of an apartment in tenement housing (the prevalent type of popular housing in Mexico), while the other relies on newspaper ads, notarial records, and other sources to estimate property values and rental yield (rental revenue relative to property values). From these wage and rental income series, we calculate rental–wage ratios that are broadly representative of the income gaps between the wealthy and unskilled workers. We find that, at the end of the eighteenth century, inequality moderately increased, followed by a more egalitarian period in the first half of the nineteenth century, and a ballooning in the last quarter of the nineteenth century that persisted into 1930. While inequality receded after the insurrection in the 1810s, it remained high after the Mexican Revolution. We hypothesize that inequality was sensitive to economic growth, and that generalized violence did not universally temper inequality.