Portage Township is located in southeastern Cambria County around the coordinates . The township surrounds the borough of Portage and touches the borough of Cassandra on its northeast border. The unincorporated community of Spring Hill is in the southwest part of the township, just south of Portage borough. The southeast border of the township follows the Blair County line and approximately follows the crest of the Allegheny Front, the height of land between the Susquehanna River basin to the east and the Ohio River drainage to the west. The Little Conemaugh River flows west through the northern part of the township, leading to the Conemaugh River in Johnstown.