Wairau was a parliamentary electorate in the Marlborough Region of New Zealand. It was one of the initial 24 New Zealand electorates and existed from 1853 until its abolition in 1938, when it was succeeded by the Marlborough electorate. The electorate had 13 representatives during its existence. The 1861 election in the Wairau electorate was notable in that a later Premier, Frederick Weld, was unexpectedly and narrowly defeated by William Henry Eyes.