Use a public people-search website
Check county property tax records
Search voter registration records where available
Look up business filings and professional licenses
Search social media profiles for location clues
Review public phone directories
Search court records and public legal filings
Check alumni directories or association directories
Search old posts, comments, or tagged photos for location hints
Ask mutual contacts if they can share the address
Use a return address from mailed correspondence if you already have it
Search online obituaries or family notices for relatives’ addresses
Contact the person directly and ask for their address
Hire a licensed private investigator if you need lawful assistance