Common Spellings:
* Sidney: This is the standard and most common spelling.
* Sydney: This is the spelling used for the city in Australia. While some people might spell their name this way for this reason, it is not the traditional spelling.
Less Common Variations:
* Sidonie: This is a French variation of the name.
* Sidonia: This is another variation, often used in some countries.
Important Note: While these variations exist, it's important to remember that "Sidney" remains the most common and widely recognized spelling.