Kenyatta, 51, the son of Kenya's first president, becomes the second sitting African president to face charges at the International Criminal Court over allegations he helped orchestrate the vicious tribe-on-tribe violence that marred Kenya's 2007 presidential election.
Before the March 4 vote, the top U.S. official for Africa warned of "consequences" if Kenyatta was voted into office. European countries offered similar warnings. But the U.S. ambassador and European ambassadors were in attendance at Tuesday's ceremony, and analysts say they doubt the warnings of consequences will amount to very much.
Kenya is the lynchpin economy for East Africa's economy and the West's most vital security partner. Kenyan troops are helping battle al-Shabab militants inside Somalia, and Kenya hosts a U.S. military base near the Somali border.
Kenyatta — the son of Jomo Kenyatta — won the country's March 4 election victory with 50.07 per cent of the vote. That win was challenged by outgoing Prime Minister Raila Odinga and civil society groups that complained of myriad anomalies in the voting process, but the Supreme Court upheld Kenyatta's win.
That court process, as well as requests by Odinga for peace, helped Kenya avoid the bloody deaths the country saw for two months in late 2007 and early 2008, when more than 1,000 people died in postelection violence.
Kenyatta has insisted he is innocent on allegations he helped orchestrate the violence and has pledged to co-operate with the ICC. His trial is scheduled to begin in July.
Kenyatta's deputy, William Ruto, faces similar charges at the ICC. His trial is set to begin in May.
Even as thousands cheered the dignitaries arriving at the Nairobi sports stadium, some in the crowd had Kenya's past violence on their mind.
"Kenyatta should put reconciliation as his priority. He must make sure we come as one nation," said Ndungu Kariuki, a 35-year-old engineer who was at the ceremony. "The charges against Uhuru are framed I was affected by the postelection violence and I know what happened. Kenyatta will be free."