The A8 is a major road in Scotland, connecting Edinburgh to Greenock via Glasgow. Its importance has largely diminished following the construction of the M8.

The A8 begins (as roads in Scotland are defined to "begin" from the end nearest to Edinburgh) on Princes Street in Edinburgh in the shadow of Edinburgh Castle. The road continues westwards through into the suburbs of the city, often with an accompanying bus lane. Only once the road reaches the City Bypass does it become a primary route, leading out past Ingilston and Edinburgh Airport.

At Newbridge, the A8 meets the M8 and M9. From here to Newhouse, the road has been renumbered the A89 and the A8 notionally ceases to exist for now.

The A8 re-emerges in Newhouse connecting to the temporary terminus of the M8 at junction 6. Here, the A8 is the weak link in the M8 route approaching Glasgow. This section has seen almost constant roadworks in an attempt to bring it up to motorway standard, a project which is finally timetabled for completion.

At junction 8, the A8 diverges and the M8 resumes a course for central Glasgow. The A8 winds through suburban streets into the city centre, and the road splits to negotiate the tricky one-way system, crossing the Clyde near the Gorbals. From there it leads a path out of town, once again dovetailing to meet the M8 near Bishopton.

The A8 becomes the primary route again at the end of the M8 and takes traffic past Port Glasgow west to its terminus in Greenock.