Large flags were erected across the capital hailing Raisi as a “martyr of service” while others bid “farewell to the servants of the underprivileged”.
Some residents of Tehran received texts urging them to attend Wednesday's event, AFP reported.
Footage reported by state TV showed streets filled with mourners, many of them holding photos of Raisi or Iranian flags.
Their funerals began Tuesday in the city of Tabriz and the Shiite clerical center of Qom, attended by thousands of mourners.
After a procession in the capital on Wednesday, Raisi's body will be taken to the South Khorasan region and then to his hometown of Mashhad in the northeast.
He will be buried in the city after a funeral at the Imam Reza shrine on Thursday evening.
Raisi, a hard-line cleric, has been a very divisive figure in Iran. While serving as a prosecutor in the 1980s, he oversaw the executions of dozens of opposition activists.
He brutally cracked down on protesters angry over the 2022 killing of 22-year-old Mahsa Amini. She died three days after being detained by the capital's morality police for violating Iran's strict rules requiring women to cover their hair. Hijab or headscarf.
But his ultra-conservative views won him favor with regime supporters, and Raisi was seen as a possible successor to Ayatollah Khamenei.
