It said the decision is part of its previously announced TreeHouse 2020 multi-year restructuring programme to reduce its cost structure and improve its profit margin.
Reports in the US, unconfirmed by TreeHouse, suggest the company is also planning to shutter an office in Omaha.
It is understood the employees in St Louis mainly work in administrative roles.
TreeHouse said the work carried out at St Louis will be consolidated into the company’s existing facilities in Oak Brook, Illinois.
It said costs associated with the office closure are expected to be incurred primarily over the three quarters ending 30 June 30, 2019 and will total approximately US$7.8m.
Steve Oakland, CEO and president of TreeHouse Foods, said: “Our decision to close St. Louis was not taken lightly, and we are committed to providing employee assistance through this challenging transition.
“As we streamline our organisation into four divisions (from five) and build our commercial excellence capabilities, it is both prudent and strategic that we also consolidate our administrative locations.”
TreeHouse has a network of more than 40 manufacturing facilities across the US, Canada, and Italy.
In December it was revealed it is planning to sell its US snacks business.