The demonstration took place near the residence of Iran’s Supreme Leader Ayatollah Seyed Ali Khamenei.
Participants carried Iranian flags and posters of Ayatollah Khamenei while chanting slogans against Israel and the US.
Despite threats from US President Donald Trump to “evacuate Tehran”, many families, including those with children, joined the rally.
Police and members of the armed forces were also present at the demonstration.
Regional tensions have escalated since Friday, when Israel launched airstrikes on multiple sites across Iran, including military and nuclear facilities, prompting Tehran to launch retaliatory strikes.
Israeli authorities said at least 24 people have been killed and hundreds injured since then in Iranian missile attacks.
Iran said at least 224 people have been killed and more than 1,800 wounded in the Israeli assault.
