Chief Justice David Maraga on Thursday cast his vote in West Mugirango, Nyamira county.
Maraga voted a few minutes past 2pm at Bosose primary school.
But he did not comment on the election exercise when asked to by the media.
"I cannot comment on the election process, I have voted and that is all," he said.
Maraga was on the seven-judge bench that nullified President Uhuru Kenyatta's election.
He ordered fresh elections within 60 days, which led to outrage among Jubilee supporters and leaders.
Uhuru went on to call the Supreme Court judges "wakoras", saying although he did not agree with the decision, he respected it.
Maraga and Uhuru were seen together for the first time during Mashujaa Day celebrations in Nairobi last week.
On Wednesday, Maraga said the Supreme Court could not hear a case seeking to stop today's repeat presidential election as there was a quorum hitch.
Uhuru and DP William Ruto also voted on Thursday and called for peace.
One person in Kisumu where police are firing live bullets and tear gas at Opposition supporters who are boycotting the election.
NASA strongholds have registered low voter turnout.
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