How long the duo has been engaged is unknown, but Hayes set off speculation earlier this week during an appearance on CBS' "The Talk," where he sported a band on his left ring finger.
Hayes' representative told RumorFix, "Sean Hayes and Scott Icenogle have been together for eight years. They are not yet married, but they have been engaged for quite some time."
Hayes, who is best known for his award-winning work as Jack McFarland on "Will & Grace," came out in a 2010 interview with The Advocate.
Hayes made his Broadway debut in the revival of Promises, Promises, earning a 2010 Tony nomination for Best Actor in a Musical. He was also seen in the City Center Encores! summer production of Damn Yankees.