Treatment of insulin-dependent diabetes mellitus, also known as Type 1 diabetes mellitus, requires delivery of exogenous insulin via injection or pump. An alternative to syringe-based subcutaneous delivery of insulin involves use of microneedles. These < 300 μm diameter, 50-900 μm long needle shaped devices may be used for intradermal delivery of insulin. Benefits associated with microneedle-based delivery of insulin include minimal training for use, painless insertion, as well as the potential to combine microneedles with sensors and drug delivery devices to create an autonomous artificial pancreas. In this review, the efforts of academic and industrial researchers over the past decade to examine the functionality of microneedles for delivery of insulin, including insulin-containing nanomaterials, via in vitro, ex vivo, and in vivo studies are considered.