A lark, early bird, morning person, or an A-person, is a person who usually gets up early in the morning and goes to bed early in the evening. The term relates to the birds known as larks, which are known to sing before dawn. Human "larks" may sleep from around 10 p.m. to 6 a.m., and tend to feel most energetic just after they get up in the morning. They are thus well-suited for working the day shift.

Larks are passerine birds of the family Alaudidae. Larks have a cosmopolitan distribution with the largest number of species occurring in Africa. Only a single species, the horned lark, occurs in North America, and only Horsfield's bush lark occurs in Australia. Habitats vary widely, but many species live in dry regions. When the word "lark" is used without specification, it often refers to the Eurasian skylark (Alauda arvensis).