State TV says the meeting between the spiritual leader and Prime Minister Haider al-Abadi was underway this morning but provided no immediate details.
The meeting has symbolic significance because al-Sistani, believed to be 86 years old, has shunned all politicians in the past years in protest of the way they run the country.
Al-Sistani lives in the Shiite holy city of Najaf, 160 kilometers (100 miles) south of Baghdad, and rarely appears in public.