It had a population of 1,395,855 in 2020 according to the latest official census, and its principal city is Louisville, Kentucky.

It is now the primary MSA of the Louisville/Jefferson County–Elizabethtown, KY-IN Combined Statistical Area, as defined by the United States Bureau of the Census in 2000 and recently redefined in 2018.

[4] In 2020, the Census Bureau measured the combined statistical area's population at 1,601,309.

In 2023, the Bardstown μSA was dissolved with Nelson County being added to the Louisville MSA and Scottsburg, Indiana μSA was dissolved, no longer considered a statistical area by the OMB.

The larger Louisville/Jefferson County–Elizabethtown CSA adds the Elizabethtown, Kentucky, MSA, consisting of Hardin and LaRue Counties.