Reform and opening-up (Chinese: 改革开放; pinyin: Gǎigé kāifàng), also known as the Chinese economic reform or Chinese economic miracle, refers to a variety of economic reforms termed socialism with Chinese characteristics and socialist market economy in the People's Republic of China (PRC) that began in the late 20th century, after Mao Zedong's death in 1976. Guided by Deng Xiaoping, who is often credited as the "General Architect", the reforms were launched by reformists within the ruling Chinese Communist Party (CCP) on December 18, 1978, during the Boluan Fanzheng period.

A parallel set of political reforms were launched by Deng and his allies in the 1980s, but eventually ended in 1989 due to the crackdown on the Tiananmen Square protests, halting further political liberalization. The economic reforms were revived after Deng Xiaoping's southern tour in 1992. The reforms led to significant economic growth for China within the successive decades; this phenomenon has since been seen as an "economic miracle". In 2010, China overtook Japan as the world's second-largest economy by nominal GDP, before overtaking the United States in 2016 as the world's largest economy by GDP (PPP).

The Chinese Communist Party (CCP) carried out the market reforms in two stages. The first stage, in the late 1970s and early 1980s, involved the de-collectivization of agriculture, the opening up of the country to foreign investment, and permission for entrepreneurs to start businesses. However, a large percentage of industries remained state-owned. The second stage of reform, in the late 1980s and 1990s, involved the privatization and contracting out of much state-owned industry. The 1985 lifting of price controls was a major reform, and the lifting of protectionist policies and regulations soon followed, although state monopolies in the commanding heights of the economy such as banking and petroleum remained.

In 2001, China joined the World Trade Organization (WTO). Not long after, the private sector grew remarkably, accounting for as much as 70 percent of China's gross domestic product (GDP) by 2005. From 1978 until 2013, significant growth occurred, with the economy increasing by 9.5% a year. Hu Jintao and Wen Jiabao's administration took a more conservative approach towards reforms, regulated and controlled the economy more heavily after 2005, reversing some reforms.

Before Deng Xiaoping's reforms, China's economy suffered due to centrally planned policies, such as the Great Leap Forward and the Cultural Revolution, resulting in stagnation, inefficiency, and poverty. Prior to the reforms, the Chinese economy was dominated by state ownership and central planning. From 1950 to 1973, Chinese real GDP per capita grew at a rate of 2.9% per year on average, albeit with major fluctuations. This placed it near the middle of the Asian nations during the same period, with neighboring countries such as Japan, South Korea, Singapore and then rival Chiang Kai-shek's Republic of China (ROC) outstripping mainland China's rate of growth. Starting in 1970, the economy entered into a period of stagnation, and after the death of Mao Zedong, the CCP leadership decided to abandon Maoism and turn to market-oriented reforms to salvage the stagnant economy. In September 1976, Mao Zedong died, and in October, Hua Guofeng together with Ye Jianying and Wang Dongxing arrested the Gang of Four, putting an end to the Cultural Revolution. Hua's break with Cultural Revolution era economic policies were consistent with the 1975 reform agenda of Deng Xiaoping. Hua made national economic development a matter of the highest priority and emphasized the need to achieve "liberation of productive forces". He "combined Soviet-style big push industrialization with an opening up to the capitalist world" and under his leadership, China opened its first Special Economic Zone and launched major efforts to attract foreign direct investment.

Economic reforms began in earnest during the "Boluan Fanzheng" period, especially after Deng and his reformist allies rose to power with Deng replacing Hua Guofeng as the paramount leader in December 1978. By the time Deng took power, there was widespread support among the elite for economic reforms. From 1978 to 1992, Deng described reform and opening up as a "large scale experiment" requiring thorough "experimentation in practice" instead of textbook knowledge. As the de facto leader, Deng's policies faced opposition from party conservatives but were extremely successful in increasing the country's wealth.

Major reforms (including rural decollectivization, SOE reform, and rural health care reform) almost always began first as decentralized local experiments subject to intervention from high level Communist Party officials before they were more widely adopted.

In 1979, Deng Xiaoping emphasized the goal of "Four Modernizations" and further proposed the idea of moderately prosperous society. The achievements of Lee Kuan Yew to create an economic success in Singapore had a profound effect on the CCP leadership in China. Leaders in China made a major effort, especially under Deng Xiaoping, to emulate his policies of economic growth, entrepreneurship, and subtle suppression of dissent. Over the years, more than 22,000 Chinese officials were sent to Singapore to study its methods.