Around 300 sixth form and college students will see an increase in their school transport costs.
It affect students where West Sussex County Council arranges their transport, for example by coach, minibus or taxi.
The charge will increase from £427 to £600 per annum.
The county council points out that the majority of West Sussex students will not see any changes to their travel arrangements.
WSCC is encouraging students affected by the change to find out if they are eligible for a bursary to help them meet the increase.
Students with special educational needs and disabilities (SEND) from families on a low income will not be affected by the change, and will continue to have their charges waived.
The decision was taken following a consultation.
Richard Burrett, the county council’s Cabinet Member for Education and Skills, said: “I would encourage students and families to find out if they are eligible for a bursary if they are worried about funding this increase.
“Each college and school administers a 16-19 Bursary Fund to help with education costs, including transport, for students from families on a low income.”
Mr Burrett said it had not been an easy decision to increase the charge.
He said: “Unfortunately we are simply unable to keep subsiding transport for students to the extent we have done in the past. It is not sustainable for us.
“The cost we charge had fallen behind the cost of equivalent journeys on public transport so we simply can no longer subsidise the charge to that extent.
“We acknowledge we could have done more to keep the cost charged over the last few years in-line with increases in equivalent journeys and in line with the amount paid by students in other counties.”
The council provides assistance with transport to eligible pupils in the county, but it does not have a legal responsibility to provide free transport for Post-16 students.
The majority of students walk, cycle, or pay for their own travel to school or college.
Many students also use commercial bus and train operators’ student discounts which have been set up in partnership between the county council and transport operators.