Answer

In Jain tradition, there is not one universally fixed “first Jain muni” in the way there is a first Tirthankar.

If you mean the earliest Jain ascetic or the one who first established the path of renunciation, that is generally understood to be Bhagwan Rishabhdev, also called Adinath.

Explanation

• Rishabhdev is the first Tirthankar in Jainism.
• He is also regarded as the one who first taught people the values of renunciation, discipline, and monastic life.
• Later, many disciples and ascetics followed this path, and the Jain muni tradition developed fully.

Spiritual Understanding

Rishabhdev represents the beginning of organized spiritual life in Jain Dharma. He showed how to move from worldly attachment toward vairagya and self-discipline.

Takeaway

So, if you are asking in a general Jain sense, the closest answer is Bhagwan Rishabhdev (Adinath).