Alison

The big difference between Alison with one L and Allison with two is gender. Allison is used exclusively for girls, while Alison is gender-neutral, mostly in Europe. It’s a diminutive of Alice and a close cousin of Alicia. While Alison comes in second place to Allison in terms of popularity, the one-L version was the first to make it on the baby-name charts in the 1930s. It was a popular name in England and France in the Middle Ages and counts among its bearers Alison Sweeney, who hosted The Biggest Loser but became well known as Sami on Days of Our Lives.