An adjustment to net international migration estimates helped push the Tennessee capital past Rutherford County for the first time since 2015.

Nashville-Davidson County emerged as the Tennessee county gaining the most population in 2024, according to Census Bureau population estimates that were released in March.

The Middle Tennessee county added 10,413 new residents between July 1, 2023, and July 1, 2024. This was its largest year-over-year increase since 2015, the last time it earned the state’s fastest-growing tag.

The new estimates, which include annual revisions back to 2020, showed that Davidson County outpaced Rutherford County’s gains for the last two years. This ended a run from 2016 to 2022 when Rutherford County, a neighboring county to the southeast of Davidson, topped the state’s rankings.

Rutherford County’s 7,347-person increase was followed by two other counties in the middle part of the state. Montgomery County added 5,627 new residents and Wilson County netted an additional 5,596. The 3.4 percent increase in Wilson County was the second fastest one-year change in the state last year, and it is Tennessee’s fastest-growing county for the decade, adding 15 percent to its population since 2020.

The eastern third of the state saw notable increases as well, with Knox County (No. 5) adding 5,172 people and Hamilton County (No. 6) adding 4,984 people. Bradley County, situated just east of Hamilton County, entered the top 10 this year, replacing Loudon County from the 2023 list (Table 1).

Table 1

• 2024
• 2023

Tennessee’s overall pace of population change slowed from a 1.2 percent increase in 2023 to 1.1 percent in 2024. The new county-level figures were very much in tune with that trend.

Overall, 84 counties gained population in 2024, down from 90 counties in 2023. The increases were smaller in 62 out of 95 counties compared to a year ago.

Net domestic migration remained widespread and was positive in 89 counties. This was the predominant component of population change for 83 of 84 counties where the number of residents grew. The only exception was Davidson County, where net domestic migration was -2,741, but net international migration was positive at 8,879 people.

Figure 1:  Overview of 2024 Tennessee County Key Population Indicators (U.S. Census Bureau)

Net International Migration Adjustments Reflected at the County-Level

Net migration is the primary driver of Tennessee population change. The new estimates show that so far this decade, 325,000 more people have moved into Tennessee than have moved out. Most of that net gain, about 78 percent, comes from domestic, state-to-state migration.

The balance, totaling more than 73,000 people, comes from international locations.

International migration has always been a part of the population estimates. However, the Census Bureau methodology incorporates additional data this decade to make the component more responsive to events like COVID-19 and increased migrant flows into the U.S.

For the 2024 release, the bureau increased the non-U.S. born immigrants by 75 percent in the net international migration (NIM) calculation at the national level. That release also included revisions to NIM totals for 2022 and 2023. For Tennessee, the net effect was an additional 21,000 people added to the population over those two years and a record-high one-year NIM total of 27,678 in 2024 (Table 2).

While the levels of net international migration have been adjusted upwards, the bureau’s process of estimating the amount of net international migration to each of the state’s 95 counties is unchanged. It uses county-level figures from 5-Year American Community Survey (ACS) to estimate the number of residents in a county who resided in a different country one year ago.

Not surprisingly, higher levels of geographic mobility from international sources into the state’s larger and more urban counties are reported by the ACS. Therefore, those same areas also captured larger shares of the NIM increase. In future vintages, the Census Bureau is expected to evaluate other means of distributing the elevated values from 2022 to 2024 and determine if additional adjustments are needed in 2025 and beyond.