Remission of type 2 diabetes (T2D) can occur after hypocaloric diet, bariatric surgery, or pharmacological treatments and associates with improved β cell function. Here, we studied islets from nondiabetic (n = 15) and T2D (n = 21) donors. We examined whether T2D β cell dysfunction can be rescued, charted the underlying molecular mechanisms by RNA sequencing, and mined transcriptomes for drug targets. Glucose responsiveness of T2D β cells improved in 60% of preparations after 3-day culture in euglycemic conditions. This was accompanied by changes in expression of >400 genes involved in functional or inflammatory pathways. Drug repurposing and target identification analyses predicted chemical and genetic hits, including JAK inhibitors, which were validated in a β cell line, human islets, and db/db mice. Therefore, defective β cell glucose responsiveness in T2D can recover, demonstrating β cell functional plasticity. The recovery associates with transcriptomic traits, pointing to targetable defects to induce T2D remission.