The microscopic nature of Dark Energy, which dominates the Universe today and drives its accelerated expansion, is arguably the biggest question in fundamental physics today. One of the simplest candidates would be a quantum vacuum energy, were the vacuum energy computed from the Standard Model not some 120 orders of magnitude greater than that observed. String theory, as a unified theory of quantum gravity, provides several avenues to resolve this conundrum. I will give an overview of the current ideas for Dark Energy in String Theory, the insights they give us into quantum gravity itself and their connections with experiments and observations.