The awards celebrate best practice in museums, galleries and heritage sites.
Jean Kerrigan, Chair of Friends of Windmill Gardens, said: “It would be wonderful if a small community-led project like the restoration of Brixton Windmill won this competition ahead of such important heritage sites as the Tower of London. We’ve all got our fingers crossed!”
Other attractions shortlisted in the Conservation or Restoration category are the Dean Heritage Centre in the Forest of Dean, the White Tower in the Tower of London, the Extraordinary Ordsall Hall in Salford, and the Watts Gallery near Guildford in Surrey.
The results will be announced at an awards ceremony on 16 May.