Guo Jia (Chinese: 郭嘉) is a minor character in the 14th-century Chinese classic novel Romance of the Three Kingdoms by the late Luo Guanzhong, and its multiple adaptations. He is an adviser who served the warlord Cao Cao.
Guo Jia born in Yangdi County. At first, a position was sought under the orders of Yuan Shao, the most powerful warlord at that time in northern China. However, he judged Yuan Shao as an indecisive man who did not know how to make full use of talented people. Thinking that Yuan Shao had little hope of getting big things left at his service. Guo Jia was recommending Cao Cao to Xun Yu. After a discussion about the state of China at that time, they both liked it. At that time Cao Cao made Guo Jia his military advisor. During the campaign against Lu Bu, the strength of Cao Cao won three consecutive battles, forcing his enemy to retreat and quartering within the ciutt of Xiapi. By that time, Cao Cao's forces were exhausted to fight, and this one had the intention to retire.
However, Guo Jia has persuaded Cao Cao to move on and give Lu Bu time to recover. Cao Cao followed the advice and at halftime prevailed against his opponent. Cao Cao was facing the forces of Yuan Shao at the Battle of Guandu, and left leaving his home city (Xuchang) barely guarded. Seeing this opportunity, Sun Ce was planned to go north and attack Xuchang. Everyone was desperate in front of the news, but Guo Jia can still promise refused to Sun Ce, being proud and impulsive, would be murdered by his own people before reaching Xuchang. True to his prediction, Sun Ce was killed before he could cross the Yangtze River. Guo Jia finally managed to defeated Yuan Shao, solidifying his position as the most important gentleman of the Northern War.
After losing the Battle of Guandu, Yuan Shao soon died in later years. His legacy was the subject of a dispute between two of his sons, Yuan Tan and Yuan Shang. Many urged Cao Cao to take the opportunity to end the heirs. However, Guo Jia advised Cao Cao to shift his attention to the south in order to attack Liu Biao in Jing Province, and let the brothers destroy themselves by battling among them. Cao Cao accepted the advice of Guo Jia and prepared a campaign against Liu Biao. The Yuan brothers actually exhausted themselves, resulting in an overwhelmed Tan Yuan in search of Cao Cao's help. Cao Cao moved his force back to the north and easily defeated Yuan Shang, who fled to Tadun, the leader of the Wuhuan tribes. Cao Cao then conquered Yuan Tan to Nanpi and took control of the Ji Province.
Meanwhile, Cao Cao had the intention of initiating an expedition to the north to eradicate Yuan Shang and wuhuan tribes, but many feared the possibility of Liu Biao attacking from the south. Guo Jia encouraged Cao to quickly embark on the expedition to prevent a resurgence of the power of Yuan Shang. According to the advice of Guo Jia, the army traveled lightly, leaving behind most of the supplies. The resulting rapid attack caught off guard at the Wuhuan at the Battle of Mt. Bailang. Tadun was killed and Yuan was exiled in what is now Heilongjiang and Jilin. Later on, Guo Jia died of illness, he was given the posthumous name of "Marquis Zhen". A year later, after Cao Cao was defeated at the Battle of Chibi, he complained: "If Fengxiao (a stylized name of Guo Jia) was alive, I would not be in this state."
- He is one of the playable characters in the Dynasty Warriors series.