Meaning and name origin
Kellin \k(el)-lin\ as a boy's name is of Gaelic origin, and the meaning of Kellin is "slender". Kellin is a variant of Kellen (Gaelic): an ancient given name. Not generally used as a name for baby boys.
Kellin is not a popular first name for males but a somewhat popular surname or last name for all people (#71459 out of 88799, Top 80%) (Source: 2000 U.S. Population Census).
Displayed below is a comparison of the popularity of the boy name Kellin and its variant forms. Popular variation forms ranked in the Top 1000/100 are Kellan (#385), Kellen (#444), Kelan and Kaelan. (Source: 2014 Birth Name Statistics).
Kellin is also pronounced similarly to Collin▲, Cullin, Kaelin, Kalin, Kealan, Keallan, Keallin, Kealon, Keelin, Kelwin, Kelwinn, Kelwyn and Killian▲. Other suggested similar baby names are Kelltin, Keltin, Kelvin▼, Klein and Mellin. These names tend to be more commonly used than Kellin.