Renfrewshire Council's new Labour administration overturned the policy of the previous SNP council, in a move which will cost at least £520,000 a year.
The SNP, now in opposition, branded the move "risky," and said Labour was in danger of opening up a black hole in the education budget, worth more than £3 million over five years.
The move reverses the policy of the previous council, which in January 2010 limited free school transport to the national legal requirement of pupils living three miles or more from their secondary school.
That move prompted a storm of protest from parents and pupils.
The bus scheme will be in place when schools re-open in August.
The council also yesterday agreed to axe charging people with physical or learning disabilities for transport to day centres. That move will cost £40,000 per year.
Announcing the return of free buses for pupils, councillor Jacqueline Henry, education convener, said: "Bringing back free school transport will mean a significant investment by the council.
"We are going beyond the minimum legal requirement because we want to support pupils, schools and hard-pressed families across Renfrewshire."
Currently, 1400 secondary pupils receive free transport, as do 1200 primary pupils who live one mile or more from school.
As a result of the change, an extra 1058 senior pupils will be entitled to free transport.
An extra 73 pupils at Rashielea Primary School in Erskine, who lived in areas which previously qualified for free transport, will also now qualify.