There is vs There are [duplicate]

This is a reversed sentence. "Happiness and joy" is the subject, preceded by the verb, preceded by an adverb (there). To determine the proper form of the verb, place the sentence in subject / verb order, and it will become clear.

Either "is", or "are" may be correct, depending upon context, as "happiness and joy" may be a single compound subject, in which case "is" would be correct ("Happiness and joy is a common sign of a happy child"), or they may be two separate subjects, as in amalgamating two sentences "Happiness is to be found in the dictionary under the letter 'H', and joy is to be found under the letter 'J'." into "Happiness and joy are to be found under the letters H and J, respectively."