Lillan is of Scandinavian origin, derived from the Old Norse word 'hlíð', meaning 'hill'. It is often associated with the Scandinavian landscapes and nature, particularly hills and valleys. The name gained popularity in Scandinavia during the late 19th and early 20th centuries as part of a trend towards using more traditional and historical names. Today, Lillan remains predominantly used in Nordic countries, contributing to its unique and distinct identity.
The name Lillan experienced a notable decline after the first few decades of its use. In its peak years (1913-1922), it was quite popular with an average of over 7 births per year. However, it almost entirely disappeared from the record for several decades before experiencing a slight resurgence in recent years (2006-2015) with an average of around 6 births per year. Overall, there were a total of 104 babies named Lillan born over these years.