Oamaru stone is a hard, compact limestone, quarried at Weston, near Oamaru in New Zealand.

The stone is compact and hard, and is ideal for building purposes, especially where ornate moulding is required. The finished stonework has a creamy, sandy colour. Unfortunately, it is not strongly resistant to pollution, and can be prone to surface crumbling.

Oamaru stone was used on many of the grand public buildings in the towns and cities of the southern South Island, especially after the financial boom caused by the Central Otago goldrush of the 1860s. The city of Dunedin and town of Oamaru both have many fine examples of Oamaru stone edifices.

Its ease of working also appeals to sculptors. Artists employing this medium include Carissa Proffit of Dunedin.