Beginning at Springburn in Glasgow, the A803 passes through the towns of Bishopbriggs, Kirkintilloch, Kilsyth, Banknock, Haggs, Bonnybridge, Falkirk, Laurieston, ending at Linlithgow.
It connects to the A80/M80 at Haggs. It also joins on to the A801 which goes to Bathgate, Livingston, and Lanark.