* Kelsi: This is a common Spanish spelling of the name, close to the original.
* Kelsea: This spelling is also popular, particularly in Latin American Spanish.
* Kelsey: You can also use the name in its original English spelling, as many Spanish speakers are familiar with English names.
* Celsia: This is a Spanish name that sounds somewhat similar to "Kelsey."
The best option depends on your preferences and the situation.