There are 9 main Nath Yogis known as Navanath and 84 siddha Yogis. The names of the 9 Nath Yogis are listed below

Jyoti sworup (light) Aadi Nath
Parbati sworup (earth) Udaya Nath
Brahma sworup (water)  Satya Nath
Bishnu sworup (power) Santosh Nath
Sesh sworup (air) Aachal-Aachambhey Nah
Ganesh sworup (gajahasti) Gaja-Kanthad Nath
Chandrama sworup (vegetation) Siddha Chaurangi Nath
Maya sworup (fish) DaDa Matsendrya Nath
Shiva sworup (child) Gorakshya Nath

You can view the big poster of Navanath at Mrigasthali Gorakshya Temple 

Likewise, there are 84 siddhas.