The group said they ‘affirmed’ Israel’s right to defend itself in the wake of missile strikes.
G7 leaders have described Iran as “the principal source of regional instability and terror” as conflict rages in the Middle East.
The conflict between Israel and Iran has been top of the agenda at the leaders’ summit, taking place in Canada.
In a statement agreed at the summit, leaders of the world’s major economies, including Prime Minister Sir Keir Starmer, said they “affirm that Israel has a right to defend itself”.
The statement, agreed before Donald Trump left the conference early on Monday evening, also includes a call for a “ceasefire in Gaza”.
It said: “We, the leaders of the G7, reiterate our commitment to peace and stability in the Middle East.
“In this context, we affirm that Israel has a right to defend itself. We reiterate our support for the security of Israel.
“We also affirm the importance of the protection of civilians.
“Iran is the principal source of regional instability and terror.
“We have been consistently clear that Iran can never have a nuclear weapon.
“We urge that the resolution of the Iranian crisis leads to a broader de-escalation of hostilities in the Middle East, including a ceasefire in Gaza.
“We will remain vigilant to the implications for international energy markets and stand ready to coordinate, including with like-minded partners, to safeguard market stability.”
On Monday, White House press secretary Karoline Leavitt announced on X that Mr Trump would be leaving the summit early, following a dinner with heads of state.
“Much was accomplished, but because of what’s going on in the Middle East, President Trump will be leaving tonight after dinner with Heads of State,” she said.
Downing Street declined to comment on Mr Trump’s early exit.
Iran said at least 224 people had been killed in the country since strikes began on Friday, while Israeli officials said 24 people had been killed and more than 500 injured.
The back-and-forth between Israel and Iran has raised concerns about all-out war between the rival nations.
The latest conflict kicked off on Friday, when Israel launched an attack on Iranian military leaders and the country’s nuclear programme.
