The A129 is a main road in Essex, England.
The road connects Shenfield in the west and Hadleigh in the east, linking various commuter towns in the county. It forms a road link between the railway stations of Shenfield and Rayleigh. More significantly, it serves commuters heading towards either London or Southend.
In the west, its route starts in the town of Shenfield at the junction of the A1023 (51.6305°N 0.3212°E / 51.6305; 0.3212 (A129 road (western end))), where it is called Hutton Road. From the town the road soon becomes Rayleigh Road and it runs through the adjacent town of Hutton and through a rural area until it enters the boundary of Billericay and becomes London Road. In the centre of Billericay the A129 is named Sun Street,at this point the road is one way and is only accessed from the Crays Hill direction. Drivers wishing to continue on this road have to turn right on the roundabout at Sun corner onto the B1007 Laindon Road, then turn left at the roundabout onto the A176 which rejoins the A129 which then becomes Southend Road. To the south of Billericay the road enters the village of Crays Hill and becomes Crays Hill. On exiting the village it is again London Road.
The road continues to Wickford and just before it is briefly interrupted by the A132 it is a dual carriageway for a short distance. When the road recommences off the A132 it is again called Southend Road. This passes through Shotgate. Just after it leaves Shotgate there is a Pegasus crossing. On approaching Rayleigh and passing under the A130 it again becomes London Road. In Rayleigh, it is first Station Road and then Crown Hill, both for short distances. It then runs North-South and becomes the High Street and High Road and intersects with the A127 via a grade separated junction. To the south of the A127 it is Rayleigh Road and runs through Thundersley before terminating on the A13 Victoria House Roundabout in Hadleigh (51.5581°N 0.5998°E / 51.5581; 0.5998 (A129 road (eastern end))).