Sydni is a feminine given name that originated from the English language, derived from the place name Sydney, itself named after the former British Home Secretary, Thomas Townshend, 1st Viscount Sydney in 1788. The name Sydney is thought to have originated from an Old English term meaning "from the well-watered land".

The name Sydni came into use as a variant spelling of Sydney in the early 20th century, with records showing its sporadic usage in the United States and Canada from around the 1910s onwards. One of the earliest recorded examples of the Sydni spelling can be found in the 1920 United States Census, where a woman named Sydni L. Jones, born around 1898, was listed as residing in Missouri.

Throughout history, there have been several notable individuals who bore the name Sydni. One such person was Sydni Deveraux (1927-2012), an American model and actress who appeared in several films and television shows in the 1950s and 1960s, including roles in "The Bob Cummings Show" and "The Adventures of Ozzie and Harriet".

Another notable Sydni was Sydni Sterling (1919-2005), an American jazz singer and actress who performed with some of the biggest names in jazz, including Duke Ellington and Count Basie. She was also a regular performer at the famous Cotton Club in New York City during the Harlem Renaissance era.

In the field of literature, Sydni Walker (1935-2018) was a critically acclaimed African American poet and author, best known for her works exploring themes of race, identity, and social justice. Her poetry collections, such as "Lineage" and "Kin to the Dream", received widespread acclaim and numerous awards.

Sydni Berthier (1944-2021) was a renowned French classical pianist and composer, known for her interpretations of the works of Chopin, Debussy, and Ravel. She performed with some of the world's most prestigious orchestras and was widely regarded as one of the greatest pianists of her generation.

In sports, Sydni Daniels (born 1989) is an American professional basketball player who has played in the WNBA for several teams, including the Los Angeles Sparks and the Chicago Sky. She was a standout player in college at the University of Connecticut, where she helped lead the team to two NCAA championships.