What is the Korean of happy fiesta.?

There isn't a direct translation for "happy fiesta" in Korean. This is because "fiesta" is a Spanish word referring to a celebration, and the concept of a "fiesta" is not as common in Korean culture.

However, depending on the context, you could use different phrases to convey a similar sentiment:

For a general happy celebration:

* 행복한 축제 (haengbokhan chukje) - literally "happy festival"

* 즐거운 파티 (jeulgeoun pati) - "joyful party"

* 신나는 축제 (shinaneun chukje) - "exciting festival"

For a specific event:

* You could use the Korean equivalent of the event name, followed by "행복한 (haengbokhan)" - "happy"

* For example, if it's a birthday party, you could say "생일 파티 행복한 (saengil pati haengbokhan)" - "happy birthday party"

Ultimately, the best way to convey "happy fiesta" in Korean would depend on the specific situation and what you want to emphasize.