The NASA leader made the announcement at the Jacaranda Grounds a few hours after Uhuru was sworn-in.
Speaking at Jacaranda Grounds in Embakasi, Odinga said he will be sworn in as the Head of State on Jamhuri Day next month.
He insisted that he will be sworn in and get into State House the same day.
"I am not a coward, I will be sworn as president on Jamhuri Day, I am the legitimate president," Odinga declared to a rapturous crowd.
Odinga's declaration came hours after President Uhuru Kenyatta and his Deputy William Ruto were sworn-in at the Kasarani Stadium before several heads of state and a thousands of Kenyans.
He said that his swearing-in is based on the August 8 results which he claims he won.
“The servers indicated that we had 8.8 million votes while Kenyatta had 7.1million votes,” he stated.
However, police later dispersed the crowd in full anti-riot gear as they lobbed teargas.