Some 77 per cent of the almost 2000 respondents in the YouGov poll, published on Saturday, indicated they would either "fully" or "somewhat" support such a law in Germany.
In contrast, 13 per cent said they would either "fully" or "somewhat" oppose it.
The rest said they did not know.
The Australian ban, which passed the House of Representatives on Friday after getting the OK in the Senate on Thursday, will take effect in 12 months.
A YouGov survey in Germany has found widespread support for restricting access to social media. (Morgan Hancock/AAP PHOTOS)
The ban will impact platforms such as Facebook, Instagram, TikTok, Snapchat, Reddit and X.
Exemptions will apply for health and education services including YouTube, Messenger Kids and WhatsApp.
It remains unclear how the measures will be implemented, but verification will be the responsibility of tech companies - not parents.
There are no penalties for users, but companies could face fines in the millions for violations.
Most see social media as a negative for children and youth.
The German survey showed 82 per cent of respondents were either "absolutely certain" or "somewhat certain" that social media had negative effects on children and adolescents.
Nine per cent were either "certain" that platforms such as TikTok, Instagram and Facebook did not have negative effects on children and teenagers, or answered the influence question with "rather no".
The rest stated that they did not know enough about social media to be able to assess this or responded with "don't know".
Of those who more likely believed in negative effects, 26 per cent believed the content might be responsible for a negative effect, while 20 per cent feared social media could be addictive.
Some 52 per cent believed both aspects equally contributed to their belief that social media could have negative effects on children and adolescents.
One per cent stated "something else" was responsible for the negative effect or answered with "don't know".
The representative online survey was conducted between November 22 and 25 with 1976 eligible voters in Germany aged 18 and older participating nationwide.
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