Fensham Reserve is a protected native forest remnant in the Wairarapa region of the North Island of New Zealand, located north-west of Carterton.

His daughter Ruby Fensham gifted the land to the Royal Forest and Bird Protection Society in 1957, and the title was finally settled on her death in 1978.

[5] In 2024, the Forest & Bird group of volunteers that looks after the Fensham Reserve made a proposal to Carterton District Council to allocate land associated with the defunct Belvedere Hall as the beginnings of a wildlife corridor between Fensham Reserve and the nearby Tararua Forest Park.

Native birds seen in the reserve include kererū, bellbird, tūī, kākā, grey warbler, fantail and kingfisher.

It was established over a hundred years ago, sourcing water from the Mangatarere Stream to provide freshwater for irrigation, livestock, and domestic use.