Southington Township is one of the twenty-four townships of Trumbull County, Ohio, United States. The 2020 census found 3,731 people in the township.

Located in the western part of the county, it borders the following townships:

• Farmington Township - north
• Bristol Township - northeast corner
• Champion Township - east
• Warren Township - southeast corner
• Braceville Township - south
• Windham Township, Portage County - southwest corner
• Nelson Township, Portage County - west
• Parkman Township, Geauga County - northwest corner

No municipalities are located in Southington Township, although the unincorporated community of Southington lies at the center of the township.

The township is governed by a three-member board of trustees, who are elected in November of odd-numbered years to a four-year term beginning on the following January 1. Two are elected in the year after the presidential election and one is elected in the year before it. There is also an elected township fiscal officer,^[4] who serves a four-year term beginning on April 1 of the year after the election, which is held in November of the year before the presidential election. Vacancies in the fiscal officership or on the board of trustees are filled by the remaining trustees.

Students in Southington attend Southington Local Schools. It comprises Southington Elementary School, Southington Middle School, and Chalker High School. The elementary, middle, and high schools are all on the same campus.

Important highways in Southington Township include U.S. Route 422 and State Routes 534 and 305.

• Rick Badanjek, NFL player^[5]
• Mike Tyson, boxer^[6]