Brentford Ait is a long 4.572-acre (1.9 ha) uninhabited ait (river island) in the River Thames, without buildings, on the Tideway near Brentford in London, England.
[1] The ait has a gap in the middle known as Hog Hole which is apparent at lower high tides, dividing the ait into "upper" and "lower" sections which are awash with water at mean high water springs.
[3] For reasons likely connected with ownership the ancient parish of Kew in Surrey[4] included Brentford Ait in its history; the London Borough of Hounslow governs neighbouring Lot's Ait separated only by thick, shifting mud at low tide from Brentford whereas channels beside the dual ait are dredged.
The ait has borne large trees since the 1920s to screen Brentford's gasworks (since removed) from the view of Kew Gardens.
The ait is covered by willows and alder and is a bird sanctuary with a significant heronry.