National figures show that more than one in four - 26.3 per cent - of A-level entries scored an A* or A this summer, up 0.5 percentage points on 2016.
It is the first time the A*-A pass rate has risen since 2011.
In Yorkshire 23.4 per cent of exams were graded at A* or A.
The increase comes amid major changes to the qualifications, with the first grades awarded in 13 subjects that have been reformed, with a move away from coursework, modular exams throughout the course and the decoupling of AS-levels, making them more challenging for students.
Among these subjects only, results are down compared with the equivalent subjects in 2016, statistics from the Joint Council of Qualifications (JCQ) show.
When comparing 18-year-olds’ results, the proportion of A* grades for these courses is down 0.5 percentage points to 7.2 per cent, A*-A grades have dropped 0.7 percentage points to 24.3 per cent and A*-E results have fallen 0.5 percentage points to 98.1 per cent.
The 13 reformed subjects are art and design, biology, business, chemistry, computer science, economics, English language, English language and literature, English literature, history, physics, psychology and sociology.
The figures, published by the Joint Council for Qualifications (JCQ), also show that boys have pulled ahead of girls for the first time in terms of A*-A grades, and have widened the gap at the highest result alone (A*).
Overall, 8.8 per cent of boys’ entries were awarded an A*, compared with 7.8 per cent of girls - a one percentage point gap. Last year the gap was 0.8 percentage points.
In terms of A*-A grades, boys are 0.5 percentage points ahead this year, overtaking girls, who were 0.3 percentage points in front in 2016.
The statistics, for England, Wales and Northern Ireland, also show:
* The overall A*-E pass rate has fallen by 0.2 percentage points to 97.9 per cent;
* In Yorkshire the overall A*-E pass rate has also fallen by 0,2 per cent to 97.9 per cent in line with the national result.
* The proportion of entries awarded the highest result - A* - has risen 0.2 percentage points to 8.3 per cent.
Figures showed a huge spike in the number of entries for a small range of subjects, including computing, with a 33 per cent rise in the number of A-level students sitting the exam in 2017, compared with last year. This included a 34 per cent increase in female students - 816, up from 609 in 2016.
There was a 12.8 per cent increase in the number taking political studies, and a 1.7 per cent rise in those taking Spanish at A-level.
But there were dips in the take-up of other languages - with a 2.1 per cent drop in those doing French and a 4.7 per cent decrease in students sitting German.
Elsewhere, entries for history - one of the most popular A-levels by number of students - fell by 8.1 per cent.
Data showed a 3.3 per cent increase in entries for maths, but there was a significant drop in those sitting English.
This included a drop of 10.2 per cent in English language, 4.7 per cent for literature, and 11.1 per cent for the combined English language and literature subject.
Overall, entries for English subjects saw a 7.2 per cent decrease.
In Yorkshire 97.9 per cent Yorkshire and Humber 97.9% (down 0.2)
Schools Minister Nick Gibb said: “The increase in entries to facilitating subjects - those that give students the greatest choice of options at university - mean even more young people will have access to all the opportunities higher education provides.
“There has been a strong uptake in core subjects, such as maths, which continues to be the most popular A-level, with maths and further maths having nearly 25% more entries than in 2010.
“This and increasing entries to science, technology, engineering and maths (Stem) subjects bodes well for the economic prosperity of our country. It will help to grow our workforce in these sectors, allowing young people to secure well-paid jobs and compete in the global jobs market of post-Brexit Britain.”
Dr Tim Bradshaw, acting director at the Russell Group of universities, which includes York, Leeds and Sheffield, said: “It is clear from the A-level results that students are continuing to work hard, many with a view to entering university.
“Congratulations to all those who have achieved the grades they wanted.”
Pippa Morgan, head of education and skills policy at the CBI business organisation, said: “As valuable as exam results are, they are one of several factors that employers look for when hiring. Businesses value young people with positive attitudes to work and their career - as those people so often succeed in any field they pursue.
“To grow the quality and uptake of apprenticeships, it’s important the Government continue works with business on how the apprenticeship levy can best work - for companies and learners of any age. Increased flexibility is vital so businesses can fund a wider range of training that better reflects employer and individuals’ skills needs.”
Unions hail ‘hard work’ by students and teachers despite ‘rushed’ exam reforms
Education groups, campaigners and unions have responded to the latest set of A-level results, which saw historic rises against a backdrop of reforms.
Chris Keates, general secretary of the NASUWT union, said: “These results have been achieved by the hard work and commitment young people and their teachers, despite the upheaval to syllabuses and year-on-year cuts to resources.
“In the face of such turbulence, it is a tribute to the hard work and dedication of teachers and students that standards overall have been maintained.
“There are some early indications that the move to greater examined content in these qualifications may be having an impact on the outcomes achieved by some learners, although more examination of the data will be required before any definitive conclusions can be reached.
“It will be important for the awarding bodies and the regulator to study any trends in this respect as the qualification reform process continues.”
Jill Stokoe, education policy adviser at the Association of Teachers and Lecturers (ATL), said students had done well despite the “rushed-in exams”.
She said: “It is good to see that more pupils are studying maths, English, chemistry and biology at A-level, and that more are doing further maths AS, which are all important subjects to gain access to university or work. But it a shame that there has been a dip in pupils studying languages such as French and German, as well as in history.
“Rushing in exam reforms has meant that schools have had little time to prepare, and this year teachers and pupils have struggled to get to grips with the changes to A-levels, with no practice exam papers, fewer available text books and no mark-schemes.”