The Revolutions of 1989 formed part of a revolutionary wave in the late 1980s and early 1990s that resulted in the end of communist rule in Central and Eastern Europe and beyond. The period is often also called the Fall of Communism, and sometimes the Fall of Nations or the Autumn of Nations, a play on the term Spring of Nations that is sometimes used to describe the Revolutions of 1848. It also led to the eventual breakup of the Soviet Union—the world's largest communist state—and the abandonment of communist regimes in many parts of the world, some of which were violently overthrown. The events drastically altered the world's balance of power, marking the end of the Cold War and the beginning of the Post-Cold War era.

The earliest recorded protests were started in Kazakhstan, then part of the Soviet Union, in 1986 with the student demonstrations - the last chapter of these revolutions is considered to be in 1993 when Cambodia enacted a new Constitution in which communism was abandoned. The main region of these revolutions was in Eastern Europe, starting in Poland with the Polish workers' mass strike movement in 1988, and the revolutionary trend continued in Hungary, East Germany, Bulgaria, Czechoslovakia and Romania. On 4 June 1989, the trade union Solidarity won an overwhelming victory in a partially free election in Poland, leading to the peaceful fall of Communism in that country. Also in June 1989, Hungary began dismantling its section of the physical Iron Curtain, while the opening of a border gate between Austria and Hungary in August 1989 set in motion a peaceful chain reaction, in which the Eastern Bloc had disintegrated. This led to mass demonstrations in the cities such as Leipzig and subsequently to the fall of the Berlin Wall in November 1989, which served as the symbolic gateway to the German reunification in 1990. One feature common to most of these developments was the extensive use of campaigns of civil resistance, demonstrating popular opposition to the continuation of one-party rule and contributing to the pressure for change. Romania was the only country where citizens and opposition forces used violence to overthrow its Communist regime. The Cold War is considered to have "officially" ended on 3 December 1989 during the Malta Summit between the Soviet and American leaders.The Soviet Union itself became a multi-party semi-presidential republic from March 1990 and held its first presidential election, marking a drastic change as part of its reform program. The Union dissolved by December 1991, resulting in eleven new countries which had declared their independence from the Soviet Union in the course of the year, while the Baltic states regained their independence in September 1991. The rest of the Soviet Union, which constituted the bulk of the area, continued with the establishment of the Russian Federation. Albania and Yugoslavia abandoned communism between 1990 and 1992, and by the end Yugoslavia had split into five new countries. Czechoslovakia dissolved three years after the end of Communist rule, splitting peacefully into the Czech Republic and Slovakia on 1 January 1993.The impact of these events were felt in many third world socialist states throughout the world. Concurrently with events in Poland, protests in Tiananmen Square (April–June 1989) failed to stimulate major political changes in Mainland China, but influential images of courageous defiance during that protest helped to precipitate events in other parts of the globe. Three Asian countries, namely Afghanistan, Cambodia and Mongolia, had successfully abandoned Communism by 1992-1993, either through reform or conflict. Additionally, eight countries in Africa or its environ had also abandoned it, namely Ethiopia, Angola, Benin, Congo-Brazzaville, Mozambique, Somalia, as well as South Yemen (unified with North Yemen).

The political reforms varied, but in only four countries were Communist parties able to retain a monopoly on power, namely China, Cuba, Laos, and Vietnam. However, these countries, would later make economic reforms in the coming years to adopt some forms of market economy under market socialism. North Korea would switch from communism and Marxism–Leninism to Juche in 2009. The European political landscape changed drastically, with several former Eastern Bloc countries joining NATO and the European Union, resulting in stronger economic and social integration with Western Europe and North America. Many communist and socialist organisations in the West turned their guiding principles over to social democracy and democratic socialism. In contrast, and somewhat later, in South America, a Pink tide began in Venezuela in 1999 and shaped politics in the other parts of the continent through the early 2000s. Meanwhile, in certain countries the aftermath of these revolutions resulted in conflict and wars, including various post-Soviet conflicts that remain frozen to this day as well as large-scale wars, most notably the Yugoslav Wars which led to Europe's first genocide since the Second World War in 1995.