Throughout the world, Kellahan (Kellahan 
) is an extremely rare unknown gender first name. Predominantly, Kellahan is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Kellahan | New Zealand, Canada, United States, Australia |
Mr, Katie, Kevin, Reeta, Darcy, David, Diane, Donna, Geoff, Gemma, Glenn, James, Jamie, Joyce, Terry, Terri, Tracy, Nancy, Emily, Ethel, Helen, Martin, Blair, Brian, Colyn, Chris, Sam, Amy, Ken, D F, Lee, Joe, Matt, Anna, Paul, Prue, Sherry, Drew, Jack, Josh, Joan, Neil, Will, Zane, Myron, Susie, Alice, Chase, Lisa, and Shelby