Some 65.6 percent of 500 Jewish Israelis surveyed by the pro-government Israel HaYom newspaper said they would support military strikes to halt Iran's nuclear programme, and 84 percent believed the Islamic republic had no intention of reining in its alleged drive to build a bomb.
Israel and many Western countries accuse Tehran of trying to develop a nuclear warhead, a charge Iran denies.
Netanyahu in a speech to the UN General Assembly on Tuesday said Israel was ready to act alone to stop Iran making a bomb, in a warning against rushing into deals with Tehran's new leaders.
"Israel will not allow Iran to get nuclear weapons. If Israel is forced to stand alone, Israel will stand alone," Netanyahu told a UN summit, in an attack on overtures made by Iran's President Hassan Rouhani.
Israel has repeatedly advocated military force and has threatened unilateral strikes against the Islamic republic.
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A nuclear-armed Iran would be a bigger threat than North Korea, Netanyahu added, in an alarmist speech designed to counter Rouhani's recent diplomatic offensive, which has included a direct phone call with US President Barack Obama.
"As dangerous as a nuclear-armed North Korea is, it pales in comparison to the danger of a nuclear-armed Iran," he said.
"A nuclear-armed Iran in the Middle East wouldn't be another North Korea -- it would be another 50 North Koreas."
North Korea, which like Iran faces wide-ranging UN sanctions over its nuclear program, is believed to have several nuclear bombs and to have shared technology with Iran.
Some 51.4 percent of respondents in HaYom survey said Netanyahu had given a "good speech" at the UN, with only 10.9 percent disagreeing.
HaYom conducted the opinion poll on Wednesday. The margin of error was 4.4 percent.