EXHIBIT 21
CLEVELAND-CLIFFS INC.
SUBSIDIARIES
AS OF DECEMBER 31, 2023
NamePlace of Incorporation or Organization
Cannon Automotive Solutions - Bowling Green, Inc.Delaware
Cleveland-Cliffs Burns Harbor LLCDelaware
Cleveland-Cliffs Cleveland Works LLCDelaware
Cleveland-Cliffs Columbus LLCDelaware
Cleveland-Cliffs FPT Services CompanyOhio
Cleveland-Cliffs Investments Inc.Ohio
Cleveland-Cliffs Kote L.P.Delaware
Cleveland-Cliffs Minorca Mine Inc.Delaware
Cleveland-Cliffs Monessen Coke LLCDelaware
Cleveland-Cliffs Plate LLCDelaware
Cleveland-Cliffs Railways Inc.Delaware
Cleveland-Cliffs Riverdale LLCDelaware
Cleveland-Cliffs Services Holding CompanyOhio
Cleveland-Cliffs South Chicago & Indiana Harbor Railway Inc.Delaware
Cleveland-Cliffs Steel CorporationDelaware
Cleveland-Cliffs Steel Holding CorporationDelaware
Cleveland-Cliffs Steel Holdings Inc.Ohio
Cleveland-Cliffs Steel LLCDelaware
Cleveland-Cliffs Steel Management Inc.Delaware
Cleveland-Cliffs Steel Properties Inc.Delaware
Cleveland-Cliffs Steelton LLCDelaware
Cleveland-Cliffs Steelworks Railway Inc.Delaware
Cleveland-Cliffs Tek Kote Acquisition CorporationOhio
Cleveland-Cliffs Tek L.P.Delaware
Cleveland-Cliffs Tooling and Stamping CompanyDelaware
Cleveland-Cliffs Tooling and Stamping Holdings LLCDelaware
Cleveland-Cliffs Tubular Components LLCDelaware
Cleveland-Cliffs Weirton LLCDelaware
Cliffs Mining CompanyDelaware
Cliffs Minnesota Mining CompanyDelaware
Cliffs Steel Inc.Ohio
Cliffs TIOP Holding, LLCDelaware
Cliffs TIOP, Inc.Michigan
Cliffs TIOP II, LLCDelaware
Cliffs UTAC Holding LLCDelaware
Ferrous Processing and Trading CompanyMichigan
Fleetwood Metal Industries, LLCDelaware
FPT - Schlafer Division L.L.C.Michigan
FPT Cleveland, LLCMichigan
FPT Florida, LLCMichigan
IronUnits LLCDelaware
Koil Metals L.L.C.Michigan



NamePlace of Incorporation or Organization
Lake Superior & Ishpeming Railroad CompanyMichigan
Lonyo Land L.L.C.Michigan
Metallics Sales CompanyDelaware
Mid-Vol Coal Sales, Inc.West Virginia
Mountain State Carbon, LLCDelaware
Northshore Mining CompanyDelaware
Silver Bay Power CompanyDelaware
SLC Acquisition L.L.C.Michigan
SNA Carbon, LLCDelaware
The Cleveland-Cliffs Iron CompanyOhio
Tilden Mining Company L.C.Michigan
United Taconite LLCDelaware