The antonyms for the word "unhappy" are numerous and can be used to describe a vast range of emotions. Some of the most common antonyms for "unhappy" include joyful, delighted, thrilled, content, elated, and ecstatic. These words all convey feelings of happiness, satisfaction, and excitement, and can be used to describe a person's emotional state in a positive sense. Other antonyms for "unhappy" include peaceful, tranquil, relaxed, and calm, which all suggest a sense of peacefulness and contentment. These antonyms for "unhappy" can be used to describe a variety of situations or contexts, from personal relationships to professional work environments.