In names there are much similarities. Sydney could already be in Spanish because it's spelled and pernounced the same. Remember names could have diffrent spelling but the same pernounciation and meaning.
The same name can be used in Spanish.
hola mi nombre es Courtney
the name Sydney is actually the same in spanish spelled but can also be pronounced Sidnehy (Si-dneh) because in spanish e's are pronounced eh.
Sydney Fairbrother's birth name is Sydney Tapping.
Sydney's name is just Sydney. It's not spelled differently..
Sydney Chaplin's birth name is Sydney Earl Chaplin.
Sydney Carter's birth name is Sydney Bertram Carter.
Robin Sydney's birth name is Robin Sydney Heymsfield.
Sydney Wolofsky's birth name is Sydney Lynn Wolofsky.
Sydney Wong's birth name is Sydney Devonne Wong.
Sydney Pollack's birth name is Sydney Irwin Pollack.
Sydney Penny's birth name is Sydney Margaret Penny.