In Jain tradition, Raja Udayan (also spelled Udayin or Udayana) is known as the future Tirthankar, specifically the fifth Tirthankar of the upcoming Utsarpini (ascending) half-cycle of time. According to Jain beliefs, time is cyclical and divided into Utsarpini (ascending) and Avasarpini (descending) eras, and each era has its own set of 24 Tirthankars.

Raja Udayan was a contemporary of Mahavira, the 24th Tirthankar of the current Avasarpini cycle. He was a king of Vitabhaya and is mentioned in Jain scriptures as someone who will attain Kevalgyan (omniscience) in a future life and become a Tirthankar in the next Utsarpini.

Therefore, Raja Udayan is respected as a future Tirthankar in Jain tradition.