Sidney is of English origin and means 'wish, desire'. It is a unisex name, traditionally given more often to boys but has also been used for girls since the 20th century. The name gained popularity in the late Middle Ages due to its association with Sir Philip Sidney, an English poet and courtier during the Elizabethan era. Variants of the name include Sydney, Sydnie, Cidney, and Sidnee.
The name Sidny experienced varied popularity with peaks in the late '90s and mid-2000s, but has generally been less common since 2006.