The M77 motorway is a motorway in the United Kingdom. It links Glasgow and Newton Mearns. It forms the most northerly part of the A77 trunk road which links Glasgow to Stranraer in the South West of Scotland.

For the first 25 years of its life, the M77 was merely a short 1.5 mile (2.4 km) long spur which took traffic from the motorway in the Kinning Park area of Glasgow, joining onto the A77 in the Pollokshaws area. However, a large number of accidents and pollution problems caused in the Giffnock and Newton Mearns districts by commuter traffic and heavy lorries (the A77 is also the main route for ferry-bound traffic sailing to Northern Ireland), saw an extension being built to the motorway in 1994 to bypass these areas. This was fiercely opposed by environmentalists, as it meant that the motorway would cut a tranch through the historic Pollok Country Park. The fact that Newton Mearns lay in the middle of a Tory-controlled constituency however ensured that the Tory Government of the day pushed the motorway construction through to approval despite this opposition.

The latest upgrade was instigated in 2004, and this will involve exending the M77 a further 15 km south to the village of Fenwick, near Kilmarnock. This is intended to replace the dangerous 4 lane unsegregated single carriageway of the A77 which is prone to fatal accidents. This is expected to be completed by the Summer of 2005.