There isn't a direct, single Gaelic equivalent for the name Curtis. Gaelic names are often descriptive or have specific meanings. To translate, you'd need to find a Gaelic name with a similar meaning or sound. "Curtis" is believed to derive from a Roman family name, and its meaning isn't entirely clear.
Therefore, you would need to choose a Gaelic name that you feel best reflects the spirit or sound of Curtis. There's no single "correct" answer.