This article is about the current B273 to the north of Croydon. For the original B273 in Mitcham, see B273 (Mitcham).
The B273 is a short road in south London. The route was originally unclassified but had gained its number by 1932, making this an early example of a recycled number.
Starting at traffic lights on the A23 to the south of Streatham, the road first heads east along the residential Green Lane, then gradually bears round to the right as it passes through Norbury. The street name changes to Parchmore Road and soon the B274 becomes dual, with a wide central reservation which contains the Thornton Heath clock tower. We end just afterwards at traffic lights on the B266 just to the east of Thornton Heath station.