Iontophoretic devices for transdermal delivery of a sphingosine-1-phosphate receptor agonist active agent are provided. Also provided are methods of transdermally delivering a therapeutically effective amount of a sphingosine-1-phosphate receptor agonist active agent to a subject, e.g., to treat immune system disorders such as multiple sclerosis. Packaged iontophoretic systems, kits including iontophoretic devices, and methods of making iontophoretic devices are also provided.