The 2016 Act on Report on Real Estate Transactions, etc. enables the Minister of Land, Infrastructure and Transport to prohibit or restrict land acquisitions by foreign investors on the grounds of lack of reciprocity, as prescribed by a Presidential Decree. However, the government has not (yet) set forth a Presidential Decree for the implementation of the provision, hence foreign acquisitions are not currently subject to a reciprocity requirement. A 2020 proposal calls for strenghening restrictions based on reciprocity.
"CHAPTER III SPECIAL CASES CONCERNING ACQUISITION, ETC. OF REAL ESTATES BY FOREIGNERS, ETC.
 Article 7 (Principle of Reciprocity)
The Minister of Land, Infrastructure and Transport may prohibit or restrict an individual, corporation or the government of a State that prohibits or restricts a national of the Republic of Korea, a corporation or organization incorporated under the statutes of the Republic of Korea, or the Government of the Republic of Korea from acquiring or transferring land in its territory, from acquiring or transferring of land in the territory of the Republic of Korea, as prescribed by Presidential Decree: Provided, That the same shall not apply where such acquisition or transfer is necessary to implement a treaty concluded in accordance with the Constitution and any Act.[...]" (Act on Report on Real Estate Transactions, etc. (No. 13797 of 2016), last amended by Act No. 17483 of 2020, Article 7 [unofficial translation])
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"Article 2 (Definition) In this Act, “foreigner” means an individual, corporation, or organization that falls under any of the following items. <Amended May 20, 2014>
1. Individuals who do not possess Korean nationality
2. A corporation or organization that falls under any of the following items:
(a). A corporation or organization established under foreign laws and regulations
(b). A corporation or organization in which more than one-half of the members or members fall under subparagraph 1.
(c). A corporation or organization in which more than one-half of the executives, such as employees or directors, who carry out business are persons who fall under subparagraph 1.
(d). A person falling under subparagraph 1 or a corporation or organization falling under item a holds more than 1/2 of the capital or more than 1/2 of the voting rights.
[Full revision 2008. 12. 26.]
Article 3 (Reciprocity) The Minister of Land, Infrastructure and Transport shall protect citizens of the Republic of Korea, corporations or organizations established under the laws of the Republic of Korea, or individuals or corporations of countries that prohibit or restrict the acquisition or transfer of land within their country to the Government of the Republic of Korea. ㆍThe acquisition or transfer of land in the Republic of Korea may be prohibited or restricted by organizations or the government, as prescribed by Presidential Decree. However, this does not apply if it is necessary for the implementation of a treaty concluded in accordance with the Constitution and laws. <Amended 2013. 3. 23.>
[Full revision 2008. 12. 26.] [...]" (Foreign Land Land Act, Act No. 13435, July 24, 2015, amended by other laws [google translation]]
Act on Report on Real Estate Transactions, etc. (No. 13797 of 2016), last amended by Act No. 17483 of 2020, Article 7 
Foreign Land Land Act, Act No. 13435, July 24, 2015, amended by other laws [google translation]
[<a href="https://www.law.go.kr/LSW/lsEfInfoP.do?lsiSeq=191659#">Act</a>],[<a href="https://elaw.klri.re.kr/eng_mobile/viewer.do?hseq=43032&type=sogan&key=4">Act_Eng</a>],[<a href="https://www.law.go.kr/lsSc.do?menuId=1&subMenuId=17&tabMenuId=93&query=%EC%99%B8%EA%B5%AD%EC%9D%B8%ED%86%A0%EC%A7%80%EB%B2%95#undefined">Act</a>],[<a href="https://ombudsman.kotra.or.kr/eng/rli/lgs/na.do?mode=view&blNo=2105972">Other</a>]