President Uhuru Kenyatta is leading the nation in marking event.
Malawian President Lazarus Chakwera is in the country and is expected to attend the event.
On this day, Kenyans used to celebrate heroes who fought for their independence from Britain but has since been expanded to recognise individuals who have made outstanding contribution to the country in various fields, including sports, medicine, education among others.
The government had announced that only 3,000 people with invitation cards would be allowed into the stadium.
A heavy downpour early Wednesday did not dampen the mood with locals braving rains to line up waiting to access the stadium which has 15 terraces.
This is the first time in history that the national fete is being held in Kirinyaga County.