En ettas dagbok is a 1982 Viveca Sundvall children's book,[1] and the first book in the Mimmi series.

Written as a diary, it is set between 16 August-30 April the year Mimmi attends the first grade at school.

Together with Roberta Karlsson och kungen and Vi smyger på Enok they were later all released in a collection called "Mimmis bok".

In 1985, a TV series based on the book was made.

Mimmi's two years older friend goes to third grade.