The official IRNA news agency said Putin landed in the capital at around 1:15 pm (0945 GMT).
Putin to meet Ayatollah Khamenei during Iran visit: Kremlin
He will hold talks with supreme leader Ayatollah Ali Khamenei and President Hassan Rouhani on the one-day visit, while also taking part in a summit of gas exporting countries.
Russia and Iran have been the main international backers of Syrian President Bashar al-Assad since an uprising broke out against his rule in 2011, swiftly escalating into a civil war.
World powers to help Iran redesign reactor as part of nuclear deal
Moscow launched a bombing campaign in support of Assad's forces on September 30 which it has stepped up since the Islamic State blew up a Russian airliner over Egypt's Sinai Peninsula on October 31, killing all 224 people on board.
Iranian court sentences Washington Post reporter Rezaian to prison
Moscow says its air strikes target Islamic State and other "terrorists," but rebels and their backers say moderate and militant opposition fighters have borne the brunt of them.
Tehran, meanwhile, has provided its Damascus ally with financial and military aid, including advisers from its elite Revolutionary Guards.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ