King George's Fields is a Local Nature Reserve, Borough Grade II, in Monken Hadley in the London Borough of Barnet. The twenty hectare site consists of a patchwork of fields, intersected by overgrown hedgerows, narrow strips of woodland and small streams. There are a number of magnificent old oaks, and breeding birds include sparrowhawk, stock dove, bullfinch, willow warbler and chaffinch. There are also a number of common butterflies and the uncommon chimney sweeper moth. It is one of many King George's Fields all over the country, established after the death of George V, who died in 1936, in his memory.
There are entrances from Hadley Green Road, Burnside Close and South Close. On the other side of Hadley Green Road is Hadley Green, the traditional site of the Battle of Barnet in the War of the Roses in 1471. The London Loop walk passes through the site.