As the group arrived, a senior Iraqi politician urged US forces to free Iraqi women in detention in a bid to save the journalist.
The deadline set by Carroll's kidnappers, who have threatened to kill her unless American forces release all Iraqi women in military custody, passed on Friday and no word has been heard on her fate since.
Carroll, 28, was abducted on 7 January in west Baghdad. A delegation from the Council on American-Islamic Relations flew to Baghdad from neighbouring Jordan in a bid to increase momentum towards Carroll's release.
Speaking upon arrival at Baghdad airport on Saturday the group's executive director, Nadi Awad, said: "We are the only people who have come from outside of Iraq to call for Jill's release and we are very hopeful they will hear our message on behalf of American Muslims. Harming her will do them [the kidnappers] no good at all. The only way is to release her."
Meanwhile, Busho Ibrahim Ali, the deputy justice minister, said the Iraqi authorities have asked the US to release six of the nine Iraqi women and that he expected them to be freed on Monday or Tuesday.
Ali said: "I am making some contacts with the American side to hasten their release because this action might help hastening the release of the kidnapped journalist."
US officials have confirmed that they are holding nine Iraqi women detainees, but declined to comment on whether any were soon to be freed.
American policy is not to negotiate with kidnappers, but US hostage situation specialists are chasing multiple leads, including talks with Sunni Arab politicians who may have links to those behind the kidnapping, to try secure Carroll's freedom.