The Ayrshire Coast Line is one of the lines within the Strathclyde suburban rail network in Scotland. It has 26 stations and connects the Ayrshire coast to Glasgow. There are three branches, to , and , all running into the high level at .
The route is operated by ScotRail.
The Ayrshire Coast Line consists of lines that were formerly part of the Glasgow and Paisley Joint Railway, the Glasgow, Paisley, Kilmarnock and Ayr Railway, the Ardrossan Railway and its Largs Branch extension.
The line to Ayr was electrified and Class 318 electric multiple units introduced by British Rail in September 1986. Full authorisation for the electrification had been given in October 1982. These were supplemented by occasional use of Class 303 and Class 311 EMUs, then in use on the Inverclyde Line.
These EMUs replaced the Class 101 and Class 107 DMUs that had served the line for over 30 years. Class 126 DMUs were also used on the line, but they succumbed to old age in the early 1980s.
As of May 2025, There are 4 trains per hour running every 15 minutes between Glasgow Central and Kilwinning, 2 of these continue to Ayr while 1 an hour serves Ardrossan Harbour and Largs each. Extra trains run at peak hours, with all trains calling at Paisley Gilmour Street, Johnstone and Kilwinning. There are occasionally extra services which run to/from Ardrossan Harbour to connect with CalMac sailings to/from Brodick on Arran, There is a 2 hourly service which runs between Kilmarnock and Ayr which calls at Troon and at Prestwick Town* and up to hourly at peak time's. On a Sunday, there are 3 trains an hour, 2 to Ayr and 1 to Largs and 4 trains per day to/from Ardrossan Harbour to connect with ferries, There are no Sunday services to/from Kilmarnock.
The line runs along the same Glasgow and Paisley Joint Railway route as the Inverclyde Line as far as , using different platforms at Paisley Gilmour Street, where it turns south west towards Kilwinning on the route of the former Glasgow, Paisley, Kilmarnock and Ayr Railway. Here the line branches in two, with one branch running south along the coast to Troon and Ayr. This branch also serves Prestwick Airport station, which opened in 1994. The other branch runs north along the coast to Ardrossan or Largs, becoming a single track for passenger trains after Saltcoats. Beyond Ayr, 'Sprinter' DMUs continue south towards Girvan and Stranraer.
The line connects with ferries at Ardrossan to Brodick on the Isle of Arran and at Largs to Great Cumbrae.