Methodology — The Foreign Residents Index

Source: Foreign Residents by Local Government (Ministry of the Interior and Safety) — Ministry of the Interior and Safety (행정안전부), taken from its open API on Korea’s public data portal (dataset 15107331). Licence: no restriction on use, as stated on the dataset page. Count year: 2023 (the source carries 2007~2023). Retrieved: 2026-09-10.
How the ranking is made: The count of foreign residents per province, as published. No weighting and no adjustment. The source puts one year per row with the seventeen provinces as columns, so we transpose the latest year’s row into rows. As a check, the seventeen provinces must sum exactly to the published total (2,459,542), and the build fails if they do not. The year-on-year figures come from the same source’s previous-year row, not from anywhere else.
The items are all seventeen provinces: Nothing to pick and nothing to cut. The province names are the same strings as the Destinations Index — the two indexes cover the same item set, and if the labels drifted apart you could no longer read one against the other.

Limits worth knowing before you cite this

“Foreign residents” is not the same as foreign nationals. This count includes people who have taken Korean nationality, and their children. If you want a nationality-based figure, the immigration service’s resident-alien statistics give a different number.
The count year lags the present. It is compiled once a year and the yearbook takes time to appear, so 2023 is the most recent figure available. We do not present it as more current than it is.
These are absolute numbers, not shares of population. That the top province is also the most populous explains much of the order. A per-capita rate would need a second source, and it is not what this index measures.
It follows registered address. Where a registered address and the place someone actually lives differ, especially around the edges of the capital region, the ranking does not see it.