To provide a fireproof covering unit for steel pipe column having excellent fire resistance and capable of providing excellent construction property at site and sufficient fire resistance even if its thickness is reduced, a fireproof external wall structure using the same, and fireproof partitioning wall structure.

A fireproof covering unit for steel pipe column 10 whose one face is made of a heat insulating sheet 12 made of a material selected from among a calcium silicate plate, a fiber reinforced gypsum board, light-weight cellular concrete or a cemented chip board and whose at least the other one face is made of a metallic plate 13 and a laminated body in which a heat insulating expansion sheet 14 is laminated on the inside of the metallic plate 13 is used.