Wairau Diversion Reserve is a coastal freedom camping area near Blenheim in the Marlborough region, situated on the northern side of the lower reach of the Wairau Diversion.

The site is accessed from the intersection of Thomas Road and Neal Road and is reserved for fully self-contained vehicles only, with a maximum stay of two consecutive nights in any four-week period.

The reserve is a popular spot for fishing and whitebait, and offers good surfing when an easterly swell is running. Mountain views are possible on clear days.

The terrain is not entirely flat, and given Marlborough's dry summers, fires are strongly discouraged at the site.