Rural areas in particular have struggled to fill posts in subjects including English, maths and science, according to data released under Freedom of Information legislation.
There were 388 primary and 341 secondary teaching vacancies.
Argyll and Bute reported the most vacant posts one week before the start of term, with 139 full-time equivalent primary and 61 secondary teachers being sought. Next was Aberdeen with 86 in total and Borders with 47.
Tavish Scott MSP, the Liberal Democrats education spokesman, said teachers would be “dangerously overstretched” until action was taken to address the gaps.
“As the school year started schools across Scotland have been desperately trying to find qualified permanent staff. Thousands of pupils faced the prospect of going back to school without a dedicated class teacher in place.
“This can only increase pressure on other teachers and make life more difficult for those pupils who need the most support. More than 4,000 teachers have been lost on the SNP’s watch,” he said, citing the party’s manifesto pledge to cut class sizes, when they have risen on average.
“Local authorities are being forced to cut back on education as a result of the SNP’s £500 million cuts to council budgets last year,” Mr Scott said.
The SNP’s spending plans will leave local authorities facing a £1 billion shortfall, according to recent analysis by the Fraser of Allander Institute. This will have “severe” consequences for Scottish schools, Mr Scott said. The Liberal Democrats are therefore proposing a one percentage point rise in income tax to fix the teacher shortfall.
A spokesman for Cosla, which represents most of Scotland’s councils, said there was “a particular problem in rural areas that needs to be addressed”.
The Scottish government said it was tackling the issue. A spokeswoman said: “While it is ultimately the responsibility of individual local authorities, the Scottish government is taking a number of actions to help recruit and retain teachers.
“We are spending £88 million this year to make sure every school has access to the right number of teachers. Where there is an issue, this tends to be in specific areas where local factors, such as house prices, can be an important part of the problem.”
The vacancy figures represent less than 1.5 per cent of the total workforce and since they were compiled, many of them will have been filled, she added.