In the late 1920s L J Wackett (later Sir) decided to design two aircraft for the RAAF, one to have a 149 kw (200-hp) radial engine, and the other to be a two-seat fighter with a 328 kw (440-hp) engine, to be known as the Warrigal I and Warrigal II.

The Widgeon II was a re-design of the Widgeon I, being described as benefiting from the experience gained in the construction and operation of the earlier aeroplane.