Sienna comes from Siena, a historic city in Tuscany, Italy, whose own name is of uncertain origin. In English, sienna is also a brown earth pigment named after the city; roasted, it becomes burnt sienna, a reddish brown. The name is pronounced see-EN-uh (/siˈɛnə/).
The city was the birthplace of Saint Catherine of Siena, one of Italy's patron saints. The name's best-known bearer is the American-British actress Sienna Miller, who broke out in the 2004 films Layer Cake and Alfie.
In the U.S., Sienna jumped from 608th in 2004 to 177th in 2006. After slipping in the early 2010s, it rose again to No. 94 in 2025, its highest rank yet, with 2,659 babies. Among the 100 most popular girls' names of 2025, it is No. 12 for how fast it climbed the rankings from 2016 to 2025.
| Sienna Miller is an American-British actress and former model who broke out with Layer Cake and Alfie in 2004, earned a 2008 BAFTA Rising Star nomination for roles including Factory Girl and The Edge of Love, played The Baroness in G.I. Joe, and then briefly stepped back amid tabloid scrutiny. |