The former Democrat Congressman from New York will appear in a federal courtroom in Manhattan to enter a guilty plea under an agreement with federal prosecutors, The New York Times, The Washington Post and other outlets reported.
In court, Weiner cried as he apologized to the teenager with whom he exchanged sexually explicit texts.
Weiner has admitted to a single charge of transferring obscene material to a minor, and won't appeal his sentence.
Weiner was already in federal custody ahead of the hearing, which lasted less than half an hour.
CNN, citing law enforcement officials, reported last September that prosecutors in the office of then-US Attorney Preet Bharara issued a subpoena for Weiner's cell phone and other records as part of an investigation into alleged "sexting" with a purportedly underage girl.
An investigation was launched last September into reports that Weiner had been sending sexually explicit messages to a 15-year-old girl in North Carolina, The Times reported. She also accused him of asking her to undress on camera, explained USA Today. A message left with a representative for Abedin seeking comment Friday morning was not immediately returned.More news: Uber threatens to fire engineer involved in Waymo lawsuit
"As reflected in the plea agreement, the resolution on terms far less severe than could have been sought reflect 'the specific circumstances of the offense conduct in this case, ' which did not feature aggravating factors often present in cases of this kind", Devlin-Brown said.
Federal Bureau of Investigation agents seized his laptop computer, finding a new cache of emails that Hillary Clinton had sent to Mr Weiner's wife, Huma Abedin, a key adviser to the Democrat presidential candidate. The two investigations - into Weiner and into Clinton's use of a private email server - briefly collided and caused then-FBI Director James Comey to publicly reveal agents had reopened the Clinton case days before the election.
Clinton recently attributed her election loss in part to Comey's announcement. A decision which came during the final push for Donald Trump and Clinton for the presidency.
Weiner, who lives in Manhattan and represented NY in Congress from 1999 to 2011, resigned after revelations that he was sending sexually explicit messages to multiple women.
Weiner continued: "While I have provided the Daily Mail with information showing that I have likely been the subject of a hoax, I have no one to blame but me for putting myself in this position". Weiner attempted to run for mayor of New York City in 2013; however, the effort was derailed after more explicit messages surfaced.