Okamoto was previously vice president of product management and marketing for graphics products at Adobe Systems. He also spent time as director of product marketing at Macromedia.
Apple CEO Steve Jobs said: "We're thrilled to have Ron leading our developer relations team. His firsthand experience at two successful Mac developers will help Apple become an even better partner for our third-party developers."
Okamoto holds a BSc in business administration from the University of Southern California.
Diane Cohn has left her position at Apple as user group program manager, to spend time with her family.
Garr Reynolds, appointed user group regional liaison for Japan last January, will replace her.
User groups are forums for sharing information about Macs. Over 600 groups exist worldwide.