Little information about Fei Yao is recorded in history; unlike other notable figures of the late Eastern Han dynasty and Three Kingdoms period, he does not have a biography in the 3rd-century text Records of the Three Kingdoms, the authoritative source for the history of that period. Information about him is found in parts of the biographies of other persons. The first mention of Fei Yao was in 220, the year when the Cao Wei state was established and the beginning of the Three Kingdoms period. He joined the Wei general Cao Zhen in suppressing a rebellion by Zhang Jin in Jiuquan Commandery. In late 221, when the tribal leader Zhiyuanduo started a rebellion in Liang Province, Fei Yao joined Zou Qi, Zhang Ji, Xiahou Ru and others in suppressing the rebellion. In early 229, when Wei's rival state Shu Han sent an army to invade the Wei fortress at Chencang, Cao Zhen ordered Fei Yao to lead troops to reinforce Hao Zhao, the Wei general defending Chencang, but Hao Zhao held his ground and the Shu invaders retreated when Fei Yao showed up. In 230, Fei Yao was promoted to the position of General of the Rear. In the same year, the Shu regent Zhuge Liang, along with the Shu generals Wei Yan, Wu Yi and others, led Shu forces to attack Wei territories in Liang Province. Fei Yao and another Wei general, Guo Huai, engaged enemy forces under Wei Yan at Yangxi, but were defeated and driven back. Around March 231, Zhuge Liang led Shu forces to attack Wei again, leading to the Battle of Mount Qi. At the time, the Wei general Sima Yi was in charge of military affairs in Liang and Yong provinces. Sima Yi, with Zhang He, Fei Yao, Guo Huai, Dai Ling and others as his subordinates, led the Wei forces to resist the enemy. In April 231, Sima Yi sent Fei Yao and Dai Ling with 4,000 troops to defend Shanggui County while he led the remaining troops to attack the enemy at Mount Qi. Zhuge Liang led a detachment to attack Shanggui County while leaving the rest of his army to attack Mount Qi. Zhuge Liang and his troops defeated Guo Huai, Fei Yao and others and collected the harvest in Shanggui County.
In ''Romance of the Three Kingdoms''
Fei Yao appears as a minor character in the 14th-century historical novelRomance of the Three Kingdoms, which romanticises the events before and during the Three Kingdoms period. In the novel, he is one of Cao Zhen's subordinates and he participates in the defence of Wei territory during the second Shu invasion. He falls into an ambush set by Jiang Wei which is meant for Cao Zhen and commits suicide after being surrounded by the enemy.