The rise is thought to have been triggered by more parents and carers walking their children to school after they switched to working from home or being furloughed during the Covid pandemic.
It represents a remarkable turnaround after walking rates sunk to a record low last year, when the numbers driven also reached their highest level.
A total of 51.2 per cent of children walked, cycled, scooted or skated to classes last September, according to the latest annual Scottish Government-funded poll by path developers Sustrans Scotland of 400,000 pupils.
That was 3.4 percentage points higher than the 47.8 per cent figure in 2019.
The provisional results of the Hands Up survey also showed a fall in numbers being driven to school for the first time in four years.
The increase was due to a rise in walking, which went up by 3.8 points from 41 to 44.8 per cent.
Pupils being driven declined by 1 point to 22.8 per cent – but it was 42.3 per cent among those at private schools.
However, cycling dipped by 0.3 points to 3.8 per cent, and scooting/skating by 0.1 point to 2.6 per cent.
Those taking the bus also declined by nearly 2 points to 14.1 per cent – a ten-year low.
The survey covered more than 70 per cent of state schools and also included nearly 33,000 nursery children.
Sustrans Scotland executive director John Lauder said: “It’s hugely encouraging to see active travel to school has reached its highest level of the last decade.
"It is doubly remarkable considering the previous year showed the highest level of children being driven to school.
"2020 was a highly unusual year, with many parents still working from home or furloughed when schools went back in mid-August.
“We are all aware that the appetite for walking and cycling increased massively during the pandemic.
"This was carried over into changes to the school run.
“Given the decrease in public transport use, it’s remarkable to see that numbers being driven to school have gone down.
"It’s possible changes to working patterns and home working for some parents mean more have been able to walk or cycle with children to school.”