Mark’s Diner is a warm and welcoming, family-friendly restaurant in Portage, MI, specializing in your favorite breakfast and lunch dishes. We offer a kid’s menu, daily specials, and lunch specials to satisfy every appetite. At Mark’s Diner, we carry on the family tradition established by the previous owners, offering great breakfast and lunch options at reasonable prices. Mark’s Diner also provides catering for breakfast, lunch, and dinner. Mark Romstadt and his wife Michelle welcome you to Mark’s Diner.