Despite birth rates falling in the last five years education chiefs said current projections could leave them without places for 235 pupils by September 2028.
In contrast there are expected to be a surplus of primary school places in borough schools in the coming years.
Walsall Council's education boss Councillor Chris Towe said officers were looking at options to meet demand for secondary places including creating a new free school or expanding existing sites.
A new education overview and scrutiny committee report showed there were sufficient secondary places for this year and next.
For the five years from September 2024, the agreed intake of 11-year-olds will be 3,696 each year. But in 2024, this will leave a predicted shortfall of 98 places.
The possible shortfall will be 134 in 2025; 67 in 2026; 110 in 2027; and 235 in September 2028.
Other data showed the number of births in the town had fallen from 3,621 in 2017/18 to 3,425 in 2020/21. Officers predict there could be as many as 907 surplus primary school places come 2025.
Councillor Towe said: “For Primary schools, since 2016 birth numbers began to reduce which have led to a forecast reduction in demand.
“The falling birth rates suggest there will be a requirement for a conversation with schools about reducing their published admission number to ensure the school does not become financially unsustainable.
“The school organisation manager will begin these conversations in winter this year.
“The situation with secondary intakes forecast there will be sufficient places for this year but shortage thereafter.
“This will mean we will have to look at developing options for additional capacity. Those options including reviewing current capacities, review the possibility of expanding and consideration of building a new free school.
“Additionally the school organisation team is reviewing the requirement for special education need places across the places in terms of pupil place planning and future proofing our requirements.”