An inlet body is for a fluid injector for a turbomachine. The inlet body includes a casing and an inlet nozzle, housed inside the casing, that serves as a seat for a mobile sealing member. The inlet nozzle includes a central duct for the fluid and an annular rim surrounding the central duct. The annular rim includes a housing for a gasket. The housing is defined by a bottom wall, an opening opposite the bottom wall, and two opposite walls which each extend between the bottom wall and the opening. The walls are tilted towards each other in the direction of the opening.