African American Cemeteries Online - Oklahoma
Cemetery Junction - Oklahoma cemeteries listed alphabetically; over 42,000 listings
Cemeteries Photographed - Oklahoma
Interment.net- Oklahoma
Oklahoma & Missouri Genealogy has a tombstone photo database
Skullyville Cemetery of the Choctaw Nation of Oklahoma
The Tombstone Transcription Project - cemeteries for Oklahoma many cemeteries here

Additional Resources

Oklahoma Obituaries enter your Oklahoma ancestor's name to search the world's largest newspaper archive; over 12 million newspaper pages
Oklahoma Birth Records
Oklahoma Marriage Records
Oklahoma Divorce Records
Oklahoma Death Records