The name "Olivia" is Latin for "olive tree." In Latin, Olivia actually is spelled Oliva. William Shakespeare is said to be the first person to alter the spelling of the name from Oliva to Olivia. This change in the spelling of the name is said to have occurred in Shakespeare's comedy "Twelfth Night."
The name "Olivia" has been used in the English-speaking world since the 18th century; however, the name did not really garner popularity until the second half of the 20th century. Some people attribute the increase in popularity of the name "Olivia" to the fact that it was the name of a main character in the popular television program "The Waltons."