His killing was announced by Israel's military. Hezbollah later confirmed his death, hailing him as "the great jihadist commander" who had "worked to confront the Israeli enemy until the last moment of his blessed life".
Israel had already eliminated most of Iran-backed Hezbollah's leadership during a war that raged between October 2023 and November 2024, when a US-brokered truce was agreed.
But Tabtabai, who was appointed as the group's chief of staff after its recent war with Israel, was killed in a rare post-ceasefire operation against a senior Hezbollah figure.
The United States imposed sanctions on Tabtabai in 2016, identifying him as a key Hezbollah leader and offering a reward of up to $US5 million ($A7.8 million) for information on him.
At least four people were killed in the strike that also injured two dozen, who were taken to nearby hospitals, medical sources said.Â
Tabtabai was born in Lebanon in 1968 to a father with Iranian roots and a Lebanese mother, according to a senior Lebanese security source.
He was not a founding member of Hezbollah but was part of its "second generation", deploying with the group to fight alongside its allies in Syria and Yemen, the source said.
Israel's military said Tabtabai joined Hezbollah in the 1980s and held several senior posts, including in its Radwan Force, an elite fighting unit. Israel killed most Radwan figures last year ahead of its ground invasion into Lebanon.
During last year's war, Tabtabai led Hezbollah's operations division and rose in rank as other top commanders were eliminated, the Israeli military's statement said.
Once the ceasefire came into force, Tabtabai was appointed chief of staff and "worked extensively to restore their readiness for war with Israel", according to the statement.
The Lebanese security source confirmed Tabtabai was swiftly promoted as other top Hezbollah officials were killed, and had been appointed chief of staff over the last year.
