President Nana Akufo-Addo has promised to introduce the measure in September to fulfil a campaign pledge.
President Nana Akufo-Addo has promised to introduce the measure in September to fulfil a campaign pledge made during last December's election that brought him to power.
Currently, access to senior high school in Ghana depends on passing an entrance exam, available places and, crucially, being able to afford the fees.
Akufo-Addo said last month that free schooling meant "more and more of our girls get access to affordable and quality education which is turn speeds up the development of our country.
"Achieving excellence in girls' education is a must if we are to shed off the evils of poverty, ignorance, and disease and put our country on the path of progress and prosperity," he added.
Girls in Ghana currently lag behind boys in school attendance by just over two years.
UN statistics from 2015 indicated girls spent an average of 5.8 years in school compared with 7.9 for boys.
Across sub-Saharan Africa, the figures were 4.5 and 6.3; globally the average was 7.7 and 8.8.
The need for girls to finish school has been the subject of many global campaigns, which have highlighted their impact on improving problem areas such as child mortality and wages.
The West Africa head of the Campaign for Female Education (CAMFED), Dolores Dickson, said girls in Ghana faced similar barriers to stay in school as in other developing countries.
Poorer families were more likely to focus on a boy's education, believing that a girl will be more helpful around the home, she added.
Public primary and junior high school in Ghana is free, although there are still costs for items such as uniforms and exercise books.
But when girls were given the chance to finish school, it benefitted everyone, she said.
Camfed has given secondary school scholarships to more than 67,000 girls in Ghana.
They "invest back in their families, paying for healthcare and other siblings to go to school", said Dickson.
Access to education should become "just as natural as breathing or.. having a meal a day" so "you don't have to think about it", she added.
Raymond Osei, who lives in Cape Coast, 150 kilometres (nearly 100 miles) from the capital, Accra, said his 13-year old daughter, Charlotte, would be going to senior high regardless.
But eradicating fees would ease the burden on family finances, said the banker, who pays about 1,600 cedi ($380, 350 euros) a year in fees and books for a private junior high school.
"For those lower income earners, it was a big blow when it (senior high school) wasn't free. Some of them end up dropping out because they cannot get enough money," he said.
Education consultant Prince Armah said the free senior high initiative was a positive move but issues of equality still needed to be addressed across Ghana.
Wealth gaps between rural and urban areas, the more affluent south and the poorer north, has an impact on schooling.
Government statistics from 2015 exams showed non-deprived districts outperformed deprived districts, with approximately 25 percent of candidates receiving above average grades.
In deprived districts, it was less than 12 percent.
Some 400 million cedi has been set aside for the scheme in this year's budget. Exact details of how the initiative will work are yet to be revealed.
But Camfed's Dickson said if Akufo-Addo's plan is successful, it will be "a fantastic opportunity for this generation".
"It means that access to education is no longer a challenge, no longer a barrier. We know the power of what education can do," she added.
"If this works people will go into the school system and have access to the school system irrespective of where you are born and who you are born to."