Thorpe Hay Meadow is a 6.4-hectare (16-acre) biological Site of Special Scientific Interest west of Staines-upon-Thames in Surrey.

Yellow rattle Rhinanthus minor, meadow-fescue grass Festuca pratensis, meadow barley Hordeum secalinum, smooth hawk’s-beard Crepis capillaris and common reed Phragmites australis are locally abundant, the last species being unusual in such dry situations.

Associated calcicole species include meadow cranesbill Geranium pratense, clustered bell-flower Campanula glomerata, cowslip Primula veris, hoary plantain Plantago media, salad burnet Sanguisorba minor and lady’s bedstraw Galium verum.

The meadow is surrounded by old hedgerows with a variety of species such as ash Fraxinus excelsior, hawthorn Crataegus monogyna, field maple Acer campestre, spindle Euonymus europaeus, dogwood Cornus sanguinea, and buckthorn Rhamnus catharticus.

Common comfrey Symphytum officinale, ragged robin Lychnis flos-cuculi, cyperus sedge Carex pseudocyperus and the uncommon aquatic liverwort Riccia fluitans...along this ditch.A footpath from Staines passes through the site.