With 1.6 million residents, Philadelphia remained the sixth most populous city in the United States in 2024, although continued population decline could be putting this ranking at risk, writes Isaac Avilucea for AXIOS Philadelphia.

Philadelphia experienced the steepest population decline of any Pennsylvania municipality from 2020 to 2024, losing 29,878 residents over that time.

The city began 2020 with more than 1.6 million residents but had dropped to 1.57 million by 2023. Still, Philadelphia added roughly 10,500 residents last year, a 0.7 percent increase from 2023.

However if the number does not stabilize or continue to grow, Philadelphia could lose its spot as the sixth most populous city to San Antonio, Texas, which added nearly 24,000 residents between 2023 and 2024, bringing its total to approximately 1.52 million.

Meanwhile in Pennsylvania, Pittsburgh recorded the largest population increase of any municipality between 2020 and 2024, and gained over 4,700 residents.

Population change accounts for both in- and out-migration, as well as births and deaths.

Read more about the most populous cities and how Philadelphia has fared in recent years in AXIOS Philadelphia.

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