The Southern Tagalog Arterial Road (also known as the STAR Tollway or CALABARZON Expressway) is a two-to-four-lane 42-kilometre (26 mi) expressway in the province of Batangas in the Philippines. It is operated by STAR Infrastructure Development Corporation (STAR – IDC). The expressway is designated as part of E2, which includes the South Luzon Expressway and Skyway.

The expressway start at the intersection with the Pan-Philippine Highway (also known as the Maharlika Highway) and the South Luzon Expressway in Santo Tomas and runs southward, near Diversion Road, to Batangas City. It passes through Malvar, Tanauan, Lipa and Ibaan.

The expressway was opened on 2001, with its first segment built between Santo Tomas and Lipa. From 2008, it was extended toward Batangas City, and from 2010, the South Luzon Expressway is connected to STAR Tollway, further shortening travel time between Manila and Batangas. The Lipa – Batangas City segment was a two-lane expressway until an addition of a second roadway between Lipa and the Ibaan-Batangas City boundary was opened in 2014. Damage on a bridge in the Ibaan – Batangas City boundary caused by Typhoon Nina (Nock-ten) required the closure of the Ibaan – Batangas City segment for bridge repairs, and diverting traffic to the parallel national roads.

With increasing traffic demand in the Batangas City – Bauan area and the Batangas Bay area, proposals to extend the expressway are laid out to decongest the existing routes through those areas. Two projects are proposed to extend the expressway to barangay Pinamucan, within Batangas City, and to the municipality of Bauan. Like the NLEX and SLEX/ACTEX before the construction of Metro Manila Skyway Stage 3, STAR Tollway is separate from the SLEX network despite being connected with SLEX since 2010.