Amirahmadi is a retired Rutgers University professor and founder of the American Iranian Council, whose shifting political positions over the years have made him a controversial figure.
Before his latest trip, Amirahmadi said his goal was not friendship between Tehran and Washington but the normalization of diplomatic relations.
"Friendly relations are different from normal relations," he said in an interview with Voice of America before traveling to Iran, adding that he hoped his ideas could help normalize ties between the two countries. He declined to say which groups inside Iran he had been speaking with.
While some pro-government media portray him as an opposition figure, some government opponents view him as an apologist for the Islamic Republic, citing his occasional defense of its leadership and institutions, including the Islamic Revolutionary Guard Corps (IRGC).
In 2019, he attended rallies organized by Iranian opposition groups abroad and described himself as a supporter of regime change. After the killing of Qassem Soleimani, however, he publicly defended both the late commander and the IRGC in media interviews.
In a recent interview with Iran's hardline Student News Network (SNN) following his return, Amirahmadi referred to slain Supreme Leader Ali Khamenei as a "martyr" and argued that "history will gradually prove that Iranians misunderstood him."
He also accused government opponents of failing to understand the realities of Iranian society.
Some conservative outlets portrayed his visit as evidence that critics of the Islamic Republic were recognizing political realities inside Iran.
SNN wrote that Amirahmadi's return "is not an ordinary event," arguing that remaining within the opposition abroad without clearly distancing oneself from groups hostile to the Islamic Republic risked being interpreted as indirect alignment with the country's enemies.
"In these circumstances, returning to the embrace of the Iranian nation and redefining one's relationship with the realities inside the country has become an unavoidable necessity," it wrote.
Not all conservative media welcomed his return. Hardline newspaper Kayhan questioned why authorities had allowed Amirahmadi into the country.
"What is Houshang Amirahmadi, America's broker and Western operative, seeking by traveling to Iran?" the newspaper wrote. "Officials must remain vigilant against this longtime spy of the Great Satan."
Some social media users rejected attempts to portray him as an opposition figure and argued that his return served the government's efforts to weaken the exiled opposition.
"They brought Houshang Amirahmadi back to Iran so they can claim the country has become a paradise and tell all opponents to return as well," one X user, Omid Roshan, wrote. "They want people to believe resistance against the government no longer works and that everyone should repent and come back."
Describing himself as a reformist, Amirahmadi unsuccessfully sought Iran's presidency in 2005, 2013 and 2017, but the Guardian Council disqualified him on each occasion.
Reports surrounding the 2005 election cited his US citizenship and some of his political positions among the factors believed to have contributed to the decision.
Some linked his return to growing speculation that Tehran and Washington could eventually restore full diplomatic relations and reopen their embassies.
"The interests of the Iranian and American people require normal diplomatic relations between the two countries," Siamak Shojaei, a university professor in Iran, wrote on X. "I hope Amirahmadi succeeds this time."
