Parnaz Azima collected her passport from authorities today and told Radio Farda she would leave Iran in the near future.
Iranian officials have charged Azima with spreading propaganda against the Iranian state.
Azima is a broadcaster with Radio Farda, the Persian-language service run jointly by RFE/RL and Voice of America.
The move comes a day after another Iranian-American, the academic Haleh Esfandiari, left Tehran following her release from jail in August on bail.
Iranian Nobel Peace Prize laureate Shirin Ebadi welcomed the decisions to allow Esfandiari and Azima to leave Iran.
"We're glad that they have been allowed to leave the country but that should have happened [straight away]. Holding them in prison or inside the country is against Iranian laws," she told Radio Farda.
"I am the lawyer for both Haleh Esfandiari and Azima and I have to say that from the beginning the cases that were created for these two were against [Iranian laws]. They haven't committed any crime; they were innocent and it's natural for them to leave the country, especially given the fact that they [are free] on heavy bail and when the date of the trial is set they have to return to Iran."
Two more Iranian-Americans remain in jail in Iran: Kian Tajbakhsh, a consultant with the Open Society Institute, and peace activist Ali Shakeri.
Tajbakhsh, along with Esfandiari, the director of the Middle East program at the Woodrow Wilson International Center for Scholars, were both shown on Iranian television in July "confessing" to accusations of working against Iran's national security.
The broadcast was condemned by the United States, as well as by human-rights groups and prominent activists.
The Reuters news agency today quoted a Tehran judge, Hossein Haddad, as saying that Tajbakhsh will be released on bail when the investigation into his case is complete.
The detentions have been seen as part of a wider government crackdown on critics and others it sees as being a threat to the regime.
Targets of the crackdown range from intellectuals and women's-rights activists to teachers and workers.
Students have also been targeted through summonses to court, threats of expulsion, suspensions, arrests, and even imprisonment.
Iranian officials have said publicly that they suspect the student movement and women's-rights activists of being part of an enemy conspiracy for a "soft subversion" of the government.