Zhongshan is situated in the south-central part of Guangdong Province and at the lower reaches of the Xijiang and Beijiang Rivers of the Pearl River Delta. It is adjacent to Nansha District of Guangzhou and Shunde District of Foshan in the north, the urban areas and Xinhui District of Jiangmen and the Doumen District of Zhuhai in the west, Zhuhai in the southeast, and Shenzhen and the Hong Kong Special Administrative Region across Lingdingyang Bay of the Pearl River Estuary in the east.

Zhongshan was referred to as Xiangshan before 1925, which stemmed from the "Universal Geography of the Taiping Era" of Song Dynasty which described Xiangshan of Dongguan County as "300 miles away from the sea in the south and a land of plentiful flowers, thus it was named Xiangshan". Xiangshan County was established in the 22nd year of Shaoxing reign in the Southern Song Dynasty (1152), and annexed the coastal areas of Nanhai, Panyu and Xinhui, which originally belonged to Guangzhou. During the Republic of China era, it was directly under the jurisdiction of Guangdong Province.

Cuiheng Village in Xiangshan County was the hometown of Sun Yat-sen. On March 12th, 1925, Sun Yat-sen passed away. On April 15th of the same year, Xiangshan County was renamed Zhongshan County in memory of Sun Yat-sen (Sun Zhongshan in Chinese). In October 1949, after the founding of the People's Republic of China, it was still called Zhongshan County, under the jurisdiction of Foshan. In December 1983, with the approval of the State Council, the name was changed to Zhongshan City, under the jurisdiction of Foshan. In January 1988, Zhongshan was approved to be upgraded as a prefecture-level city directly under the jurisdiction of Guangdong Province.

Zhongshan has an administrative area of 1,783.67 square kilometers, with 15 towns and 8 sub-districts. There is a national development zone - Zhongshan Torch High-tech Industrial Development Zone, and an economic cooperation zone - Tsuihang New District, including over 127 communities and 150 administrative villages.

In 2011, Zhongshan was crowned the "Hometown of Eaglewood in China" for its high-quality eaglewood resources and profound traditions. It is home to Zhongshan Hot Spring Resort, Changjiang Reservoir Tourist Area, Quanlin Tourist Resort, Zimaling Park, Famous Tree Garden, Zhongshan Arboretum, Jinzhong Reservoir, Wuguishan Mountain Xiaoyao Valley, Cuizhuyuan Rafting Park, Yixian Lake Park, Dachong Zhuoqi Mountain Park, Yandun Mountain Ancient Pagoda, Xishan Temple, Nanshan Guxianglin Park, Imperial Remains of the Song Dynasty, Luosanmei Mountain, Qiaotou Xiaolanghuan Park, and other attractions.

On January 19, 2019, Zhongshan was recognized for its pleasant climate by the National Climate Center, and became the first prefecture-level city in Guangdong Province to be awarded the national climate mark. The assessment report shows Zhongshan has superb natural conditions suitable for living, retirement, working and traveling with excellent air quality, a high vegetation index, pleasant ecological environment, abundant climate resources and water resources, fine water quality, diverse climate landscapes, and superior climatic conditions for tourism and vacation .

According to the Seventh Zhongshan Population Census Bulletin published on May 18, 2021, Zhongshan has a permanent population of 4,418,060 including 1,697,001 family households and 141,818 collective households. 2,383,175 males (53.94%) and 2,034,885 females (46.06%) makes up the permanent residents. 693,109 people fall in the age range of 0-14, accounting for 15.69% of the total population; 3,333,171 people fall in the age range of 15-59, accounting for 75.44%; 391,780 people are aged 60 and above, accounting for 8.87%, of which 264,160 people are aged 65 and above, accounting for 5.98%. Among permanent residents, 590,075 have an university education background (including junior college or above).

In 2020, Zhongshan's GDP grew 1.5% year-on-year to 315.159 billion yuan. The added value of Zhongshan's primary industry was 7.157 billion yuan, an increase of 17.5% year-on-year; The added value of the secondary industry was 155.678 billion yuan, growing by 1.4% from a year earlier; The added value of the tertiary industry was 152.325 billion yuan, up 1.1% year-on-year. The three-industry structure ratio was adjusted to 2.3: 49.4: 48.3.

(As of June 22, 2021)