The Milton Keynes grid road system is a network of predominantly national speed limit, fully landscaped routes that form the top layer of the street hierarchy for both private and public transport in Milton Keynes, Buckinghamshire. The system is unique in the United Kingdom for its innovative use of street hierarchy principles: the grid roads run in between districts rather than through them. This arrangement permits higher speed limits due to the absence of buildings close to the roads – although more recently some have been limited in part to 40 mph (64 km/h). The grid road system also serves an important purpose of discouraging through-traffic from travelling through neighbourhoods and thus reduces traffic noise and pollution in pedestrian areas. Motor traffic is segregated from pedestrian and leisure cycling traffic, which uses the alternative Milton Keynes redway system. Almost all grid junctions are roundabouts, and the absence of traffic lights enables free and efficient movement of traffic.

Milton Keynes is a city in Buckinghamshire, England, about 50 miles (80 km) north-west of London. At the 2021 Census, the population of its urban area was 264,349. The River Great Ouse forms the northern boundary of the urban area; a tributary, the River Ouzel, meanders through its linear parks and balancing lakes. Approximately 25% of the urban area is parkland or woodland and includes two Sites of Special Scientific Interest (SSSIs).