The Jaarso, Giarso or Jarso (Somali: Jaarso, Oromo: Jaarsoo, Arabic: جارسو) is a major northern Somali clan, a sub-division of the Dir clan family They largely live in Ethiopia, in the Oromo Region and the Somali Region, especially in and around the cities of Chinaksen, Harar and Jigjiga

As a Ali Madahweyn Dir sub-clan, the Jaarso have immediate lineal ties with the Gurgura, Akisho, Gadabuursi, Issa, the Biimaal, the Bursuk, the Madigan Dir, Gurre, Gariire other Dir sub-clans and they have lineal ties with the Hawiye (Irir), Hawadle, Ajuran, Degoodi, Gaalje'el clan groups, who share the same ancestor Samaale.

The Jarso Ali Madaweyn are a vast clan that stretch from Diida Waleed (near Jijiga) to the Awash region; they also extend onto the areas northwestern Fafan Zone. The Jaarso are the majority clan in Jarso (woreda), Funyan Bira and in the East Hararghe Zone.

The Jarso clan faced a series of problems, including Ethnic conflict, civil wars, clan border disruptions due to massive Oromo and Somali clans migration, which caused societal chaos. In response, Jaarso established a traditional constitution called Xeer Jaarso also known as “Xeerka lixda Jaarso” (The law of the six Jaarso), characterized by power-sharing principles, uniting the community in their pursuit of stability and order.

According to oral tradition, as narrated by Jaarso elders, The Jaarso Code of Conduct is older than 1200 years and In order to establish their governance and decision-making process, the elders of Jaarso held a 12-month meeting in a small village called Marrar near Jinacsani and Mullisa mountainous village between Ejersa Gora and Adari. All the six major Jaarso sub-clans participated and every sub-clan had at least one member. The elders were chosen for their knowledge of the law and wisdom and especially their knowledge for the neighboring folks. Normally a Xeer (law) to be excepted by the people has to have Multiple chieftains or clan leaders whom in this case will serve as judges and the number of the judges were 6.

While some Ethiopian tribes and Somali clans have adopted symbols or flags for cultural or political representation, there is no documented or official flag specifically associated with the Jaarso clan except the old white and red flag of Ifat.

The Jaarso are mainly found in Jarso (woreda), and northwestern Fafan Zone, in the East Hararghe Zone and are predominant clan in the historic towns of Jinacsani or Chinaksen, Funyaan Bira and Hubat today known as Ejersa Goro. The sixteenth-century ruler of Adal who conquered Abyssinia, Ahmad ibn Ibrahim al-Ghazi was born in Hubat.

Either Jinacsani or Funyan Bira is believed by archaeologist to be Dakkar, which served as the first capital of the Adal Sultanate after its founding in the early 15th century by Sabr ad-Din. Enrico Cerulli, Bahru Zewde and other historians identify Dakkar as being located one km southeast of Harar. However, Richard Pankhurst states that the city was situated near the village of Funyan Bira and G. W. B. Huntingford believes that it was in the town of Chinaksen near Jigjiga.