This article explores the impact of the Chinese Communist Revolution of 1949 on official and unofficial Sino-Iranian relations. In China, commentary about Iran became a mainstay of CCP propaganda and drew on Pan-asian themes. In Iran, two competing visions of China emerged in the pages of newspapers, magazines, and travelogues, one espoused by the state, the other by its leftist critics. One saw the victory of Mao Zedong as an inspiration, while the other held up the fate of Chiang Kai-shek as a cautionary tale for Iran. Official ties between Iranian state and the Nationalist Republic of China, established in the 1920s, became increasingly visible to Iranian elites. At the same time, unofficial ties developed between the Chinese Communist Party and the Iranian Tudeh Party, primarily through networks of student activists. These ties laid the groundwork for the emergence of Iranian Maoism as an ideological force in the 1960s. My project intervenes in this growing discourse on Sino-Iranian relations by shifting focus to social history. Inspired by Elizabeth Wynne Russell's work on diplomacy and identity, it explores the mutual influence between official and unofficial forms of Sino-Iranian interaction rather than reinforcing a dichotomy between them. State-to-state connections are examined alongside a parallel trajectory of ties, visits, and relations far less covered and documented in conventional literature, between Leftist trends among the Iranian opposition and the Chinese state at the height of the Cold War. Both the state and the opposition used international relations and the 1949 Chinese Revolution as a medium to advance competing visions of Iranian identity and the meaning of both Anti-Communist and Socialist internationalism. International conferences in Beijing, open letters on China-Iran relations, newspaper articles, and travelogues about China were linked to domestic debates about the future of Iranian society. I argue that these events set the stage for important developments among both state and opposition forces in the 1960s and 1970s, when relations with China impacted the direction and strategy of the Pahlavi state and its militant opposition. This approach foregrounds a set of relations that until now was considered mainly background to the larger drama of Sino-Iranian state-to-state interactions. A transnational framework emphasizes the global origins of the Iranian revolution and the international context in which it developed. Focusing on the external rather than internal factors that impacted the Iranian opposition highlights how the Iranian revolution played out across international borders.