Education Cabinet Secretary George Magoha on Saturday announced the 2021 KCSE results.
Jeriel Ndeda of Mang'u High School emerged as the top candidate in the country, scoring an A of 87.167.
He was followed by Mukuha Timothy Kamau of Alliance High School with 87.167 and Job Ngara of Mangu High School with 87.116.
Jeriel has said that he did not expect to be the top student although he anticipated scoring Grade A.
"I did not think I was going to be at the top of the class. I told my friends I'll just get Grade A of 84 points," he said.
In an interview with Citizen TV, Ndeda said he wants to join Maseno university to pursue a medicine course.
Magoha said boys performed better than girls in the just-released results, adding that there was gender parity.
Of the 826,809 candidates who sat for the examination, 421,318 were males while 405,559 were females.
1,138 candidates obtained an overall grade of A compared to 893 candidates in 2020.
The number of candidates with minimum university entry qualifications of Grade C+ and above rose to 145,145 in the year 2021 KCSE compared to 143,140 in 2020.
The percentage of candidates with a mean Grade of C+ and above declined from 19.03 to 17.49.