Deputy William Ruto has eulogised former Makueni MP as an iconic leader of great conscience and conviction.
Kiilu died on Tuesday at Nairobi Hospital after a long illness.
"Peter Kiilu served the country and the people of Makueni constituency with distinction," Ruto said on Wednesday.
"An indefatigable servant of unity and harmony, Honourable Kiilu was a tireless worker, bold and with fresh thoughts that transformed many lives."
Ruto said his humility, leadership and visionary style to politics will forever be remembered.
"Our heartfelt thoughts and prayers to the Kiilu family, friends and the people of Makueni. Rest In Peace."
On Tuesday, President Uhuru Kenyatta sent a message of comfort to Kiilu's family.
The President eulogised the former MP as a friendly and seasoned public administrator who served the nation with distinction.