Phu Chi Fa (ภูชี้ฟ้า), also Phu Chee Fah, is a mountain and national forest park in Thailand at the east edge of the Thoeng District, Chiang Rai Province. Phu Chi Fa is at the northeastern end of the Phi Pan Nam Range, 12 km to the southwest of Doi Pha Tang.
The mountain is part of an elevated area, the Doi Pha Mon sub-range, that rises near the border with Laos sloping towards the Mekong River. With spectacular views over the surrounding mountains, it is one of the famous tourist attractions of the Thai highlands near Chiang Rai. Tourists visit the mountain especially at dawn in order to catch a glimpse of the "sea of mist", the view of the fog-surrounded hills, with heights ranging between 1,200–1,600 m to the east of the mountain.
The weather on Phu Chi Fa is cool, averaging around 20° C. It has three seasons: hot, rainy, and cool, influenced by the tropical monsoon.
Phu Chi Fa is home to many animals. Mammals include barking deer, wild boar, palm civets. Birds include canaries, pheasants, and magpies.