The Nonsuch 30 is a Canadian sailboat that was designed by Mark Ellis and first built in 1978. It was the first the series of Nonsuch sailboats and was scaled upwards and down, to form a complete line of boats, from the Nonsuch 22 to the Nonsuch 40.

The Nonsuch 30 hull design was used to create the 1994 Nonsuch 324, which features a carbon fibre wishbone boom, more sail area and a wing keel.

The first in the Nonsuch line of boat designs, the concept of a cruising catboat was proposed by Toronto businessman and sailor Gordon Fisher. Ellis designed the boats and they were built by Hinterhoeller Yachts in St. Catharines, Ontario, Canada, between 1978 and 1989, with 1080 examples completed.

The Nonsuch 30 is a small recreational keelboat, built predominantly of fiberglass, with wood trim. It has a cat rig, an unstayed mast with a wishbone boom, a plumb stem, a vertical transom, an internally-mounted spade-type rudder controlled by a wheel and a fixed fin keel. It displaces 10,500 lb (4,763 kg) and carries 4,500 lb (2,041 kg) of ballast.

The boat was built with three different interior floor plans, the classic, ultra and nova.

The boat has a draft of 5.00 ft (1.52 m) with the standard keel and 3.96 ft (1.21 m) with the shoal keel fitted.

The boat is fitted with a Westerbeke diesel engine of 27 hp (20 kW). The fuel tank holds 30 U.S. gallons (110 L; 25 imp gal) and the fresh water tank has a capacity of 86 U.S. gallons (330 L; 72 imp gal).

The design has a PHRF racing average handicap of 180 with a high of 192 and low of 156. It has a hull speed of 7.18 kn (13.30 km/h).