Kharj's status as a city is recent, as it originally referred to a large region made up of a number of separate small towns. The largest towns historically were ASSeeh and Dilam. Other towns include Sulamiyya, Yamamah, and al-Hayathim, as well as other smaller villages and hamlets. The modern city grew out of Al-Seeh.
The Kharj region is defined largely by the wide valley known as Wadi al-Sahba (sometimes known as "Wadi al-Kharj"), where the floods of many other wadis, such as Wadi Hanifa, are deposited. In addition, there were historically several fresh water springs (called asyah or uyun) that flowed towards the surface through apertures in the earth. As a result, the Kharj district has historically been one of the richest locations in Arabia in water resources, and has supported grain production since ancient times. However, springs of al-Kharj, like those of neighboring al-Aflaj have completely dried up in the last two decades.
In previous time periods, the district was more often known as Jaww, Jaww al-Yamamah, or Al-Khadharim, though the name "Al-Kharj" was also known. The pre-Islamic legend of the tribes of Tasmi and Jadis, is set in the Kharj district. At the beginning of Islam, al-Kharj was inhabited by the Bakr tribes, especially the Banu Hanifa. In 862, the Alid clan of the Ukhaydhirites fled to al-Kharj from the Hejaz, and made its main city, Al-Khidhrima, the capital of a small state.
In the 18th century, the Kharj district was, along with the town of Riyadh, the most stubborn foe of the First Saudi State, and was among the very last areas of Najd to fall under Saudi rule. However, the district later became among the most loyal regions to the Al Saud, providing refuge to Turki ibn Abdallah from the Egyptian occupation in the 1820s, and joining Ibn Saud's campaigns in the early 20th century at an early date.
Today, Kharj houses a governmental farm, among the oldest of its kind in the country. Kharj oasis produces dates, vegetables (including carrots, cucumbers, tomatoes and lettuce) and fruits (including oranges, melons and grapes). There is also livestock and poultry, as well as horse breeding. There are also large industries for processed food. Kharj has excellent connections to other urban centres in the country, using the system of highways, railroad and airports of the capital, Riyadh, which is 50 km northwest. Kharj lies on the route to the regions of the cities Abha, 800 km, Khamis Mushayt, 775 km, and Najran, 800 km, all southwest. Kharj is located to an area of deepwater pools. There is also a water tower with a restaurant.
These days Al-Kharj is a place for tourist. It has historical places in Dilam Al-Sseeh, and others. It has fresh water called uyun. The Uyun water will be use for farmers to irrigate. So it is surrounded by many farms. Also, there are many popular places like the water tower restaurant, and a traditional food restaurant. In addition, water tower has a big place under the tower. The state of Al-Karj use it in weekends or calibrating days for activities.