Joint-stock company Ukrtransgas (Ukrainian: Акціонерне товариство "Укртрансгаз") is an independent Storage System Operator of Ukraine that ensures the operation of Ukrainian underground gas storages, and carries out retrofit and construction of main gas pipelines and facilities on them.

1173 of July 24, 1998, "On unbundling of functions for production, transportation, storage, and sale of natural gas".

[2] Until January 1, 2020, JSC Ukrtransgaz operated in 3 main areas: However, after the unbundling (a reform in Ukraine's gas industry to separate gas transportation activities) had been completed, this function was transferred to LLC GTS Operator of Ukraine.

On April 7, 2023, the National Energy and Utilities Regulatory Commission (NEURC), following approval from the EU, made a final decision to certify the SSO of Ukraine in accordance with European regulations on the security of gas supply.

[3] Certification confirms a right of JSC Ukrtransgaz to store gas not only of Ukrainian companies but also of non-residents.