First South West[2] is a bus company operating services in the English counties of Somerset and Cornwall.

First South West includes the Kernow, Truronian, Adventures by Bus and Buses of Somerset brands.

FirstGroup purchased independent Cornish operator Truronian in April 2008 and merged it into First Devon & Cornwall.

In January 2020, Cornwall Council awarded the entire tendered bus network within the county to Plymouth Citybus, consisting of 73 routes.

Kernow continues to operate their entire commercial network across Cornwall, including Tinner, University, Lizard and Coaster branded routes, as well as the 24, 27, 87 and 91.

Commencing from May 2021, First South West launched a number of services under the 'Adventures by Bus' brand across Cornwall, Devon and Somerset.

This was due to last for five years,[8] however, First South West informed Somerset Council it no longer finds the route to be viable and ended its commitment in February 2024.

[13] Until December 2006 First South West operated the last sizeable fleet of Bristol VRT double-deck buses in the United Kingdom.