On Thursday morning, Premier Annastacia Palaszczuk announced two new schools for Brisbane's inner-city and an expansion of West End State School.

One of the new schools will be built on the site of the former Fortitude Valley State School and there are a "couple of options" for the location of the new school on Brisbane's southside - with a capacity of 1200 to 1500 each.

Deputy Premier and member for South Brisbane Jackie Trad said she was confident the additional site would be secured within the current catchment of Brisbane State High School, or just outside.

The mega school has been nudging capacity for years.

BSHS takes students from its catchment - which includes West End, South Brisbane, Highgate Hill, Woolloongabba and Dutton Park - but also accommodates more than 1000 in its selective entry program for academic, sporting and culture abilities.

Many families deliberately move into catchment areas of well-performing state schools such as BSHS so their child can attend, rather than forking out for private schools.

Ms Trad said it had yet to be determined whether the new inner-south high school would also be selective.

"It will be a school to service local kids," she said.

"Whatever we land on, there'll be a very strong focus on making sure we have a school of excellence for local kids."

When asked if the move meant catchment areas could be changed - leaving some residents outside the BSHS area - Ms Trad said: "Fundamentally given all the growth in the inner-south, we can't not look at catchments generally".

But she promised all critical decision-making around the new high school would be done in full consultation with the community, with a local reference group established to help guide its development.

"It's very early and rather than put out any preliminary information that may need to change or misinformation, what we want to do is work with the current schools, our current parent cohort and our local community," Ms Trad said.

Fairfax Media has consistently reported on the ballooning numbers at inner-south schools and calls for a solution.

In 2013, the former LNP government proposed to split the BSHS campus to deal with capacity issues, with a second site at Coorparoo, but it was ditched after an angry reaction from parents and residents.

Moving Year 7 students into high school also impacted on BSHS's capacity issues, with works conducted in recent years to boost the number of students it could take.

Adding to the growth, West End State School principal Kim McNamara said about 52 per cent of the school's students lived in apartments in the area, where a glut of apartments have come onto the market.

In February, University of Queensland demographer Dr Elin Charles-Edwards said her research estimated the number of school-aged children living in the inner-city had increased 30 per cent since the 2011 Census.

Ms Trad said the announcement of new land for an expansion at West End State School came after almost $11 million promised for the school to provide eight new classrooms, a resource centre and new library.

She said securing the facility on Vulture Street opposite the current school site, and next to the police station, meant students would be able to enjoy more green open space.

Ms Trad said more detailed planning would be undertaken on the Vulture Street site for West End State School.

The cost for the site is expected to be outlined in next Tuesday's budget.

The LNP did not welcome the announcement, with Opposition Leader Tim Nicholls accusing the government of using half a billion dollars to fight off the Greens vote in the inner-city.

Mr Nicholls also said in 2013, the Queensland Schools Planning Commission said no new schools were needed for inner-city Brisbane until after 2031.

But Education Minister Kate Jones said it was a "complete and utter falsehood" that new schools were not needed in the inner-city.

"Our data clearly shows that in the zero to 5km radius, we've seen 5000 additional state students join state schooling in the last 10 years," Ms Jones said.

"And we'll see up to 4000 more students in the next five years."

Greens candidate for McConnel Kirsten Lovejoy cautiously welcomed the announcement of two new schools but said the plan needed community consultation.

What are the enrolment figures in the inner-south?

West End State School has a built capacity of 975 and there were 908 full time equivalent students enrolled at the school on day eight of the 2017 school year.

That is a 21.33 per cent increase from 2013.

The changes announced on Thursday morning will increase the capacity of West End State School to about 1500.

The prestigious Brisbane State High School, now the biggest school in the nation, has a capacity of 3435.

It had 3190 students on day eight of 2017 - a 33.53 per cent increase on the 2389 students it had in 2013.