Not knowing where your spouse is does not stop you from getting divorced in New York. It changes how the paperwork gets delivered, and it adds a step, but the case can still go forward.
Why this comes up
A divorce cannot move until the other person has been formally handed the papers. That is called service. When somebody has moved, changed their number, or simply does not want to be found, normal service is not possible.
New York has a process for exactly this situation, so the answer is almost never that you are stuck.
What the court expects first
Before allowing any alternative, a judge wants to see that you genuinely tried to find the person. That usually means checking last known addresses, asking family or mutual contacts, looking at employment, and searching public records.
The effort has to be real and it has to be documented. A judge is deciding whether it is fair to end a marriage without the other side ever hearing about it, so the search is taken seriously.
Service by publication
If the search comes up empty, you can ask the court for permission to serve by publication, which means publishing a legal notice in a newspaper the court approves rather than handing papers to a person.
It adds time and a publication cost, and the court sets the specifics. It is a well-worn path and courts grant it regularly when the search was done properly.
This page is general information about how the process works in New York. It is not legal advice and it does not create an attorney-client relationship. Whether any of it applies to you depends on your situation, which is what a consultation is for.