An object is to provide a sheet-metal turbine housing free from a risk of damage to a turbine housing even if the turbine housing connected to an exhaust-gas inlet duct part is heated, and from a risk of leakage of exhaust gas through a gap between the exhaust-gas inlet duct part and the turbine housing. A sheet-metal turbine housing includes: a scroll part formed from sheet metal and forming an exhaust gas passage of a spiral shape; an exhaust-gas inlet duct part engaged with an inlet end portion of the scroll part formed into a tubular shape, for introducing exhaust gas into the exhaust gas passage of the scroll part; and a seal unit disposed on an engagement section at which the inlet end portion of the scroll part and the exhaust-gas inlet duct part engage with each other, to close an annular gap formed at the engagement section.