The egg tart or egg custard tart (commonly romanized as dan tat)is a pastry commonly found in Hong Kong and other Asian countries, which consists of an outer pastry crust that is filled with egg custard and baked.

Custard tarts were introduced in Hong Kong in the 1940s by cha chaan tengs. They were then introduced in western cafes and bakeries to compete with dim sum restaurants, particularly for yum cha. During the economic boom of the 1950s and 1960s, Lu Yu (陸羽, Pinyin: Lù Yǔ) took the lead with the mini-egg tart. Ironically, mini egg tarts are now a common dim sum dish and are richer than those served in bakeries.

One theory suggests Hong Kong egg tarts are an adaptation of English tarts with custard filling. Guangdong had more frequent contact with the West, in particular Britain, than the rest of China. As a former British colony, Hong Kong adopted some British cuisine. Another theory suggests that egg tarts evolved from the very similar Portuguese egg tart pastries, known as pastel de nata, traveling to Hong Kong via the Portuguese colony of Macau.

Christopher Patten, the last British governor of Hong Kong, enjoyed eating egg tarts at Tai Cheong Bakery.

Today, egg tarts come in many variations within Hong Kong cuisine, including egg white, milk , honey-egg, ginger-flavoured egg, which are variations of a traditional milk custard and egg custard served in cha chaan tengs), and also chocolate tarts, green-tea-flavoured tarts, and even bird's nest tarts.

Overall, Hong Kong egg tarts have two main types of crusts: shortcrust pastry and puff pastry, traditionally made with lard rather than butter or shortening. Most Hong Kong Chinese food purists hold the egg tarts made with puff pastry in higher regard.

Unlike English custard tarts, milk is normally not added to the egg custard, and the tart is not sprinkled with ground nutmeg or cinnamon before serving. It is also served piping hot rather than at room temperature like English custard tarts.

They are sold at KFC restaurants in south-east Asia.