Sisi, 59, was declared the country's President last week after winning 96.6 percent of the presidential vote, almost a year since the ouster of Islamist leader Mohamed Morsi last year. (Agencies)
He took the oath of office for a four-year term at a ceremony held in front of the Supreme Constitutional Court's General Assembly here. Later he was given a 21-gun salute followed by the national anthem.
He is the seventh President of Egypt.
Sunday was declared a national holiday. The low-key ceremony was attended by the entire Cabinet of Prime Minister Ibrahim Mahlab as well as Sisi's wife and children.
Sisi, wearing a navy blue western suit, entered the hall walking side by side with the outgoing interim president Adly Mansour.
The ceremony, telecast live on TV, started with verses from the Quran. The inauguration will continue with ceremonies at the Ittihadiya and El-Kobbeh presidential palaces, which will be attended by several foreign representatives.
Egypt has tightened security across its capital Cairo for his inauguration amid assassination ‘threats’ recently reported by Egyptian media, warning that former army could be a target of planned attacks.
Sisi, a retired field marshal who deposed Morsi, promised to restore stability and the economy after three years of turmoil.
Morsi, who became the country's first democratically-elected president after the ouster of longtime leader Hosni Mubarak, was deposed on July 3, 2013 following massive protests calling for his resignation.
Sisi, who was army chief at the time, stepped down from his military post this year to run for President.
In the election, Sisi defeated the only other contender Hamdeen Sabahi.
He inherits a nation that is divided and weary. Experts warn that if he cannot deliver in the next year or two he could face a mass revolt, like his predecessors.
In a televised speech after the poll, Sisi said he wanted ‘freedom’ and ‘social justice’, echoing the slogan of the 2011 revolution.
He also faces a wide array of other challenges, including fixing the economy, preventing further political crises and easing poverty. More than a quarter of Egyptians live below the poverty line - most in rural areas.
Sisi has also promised to restore security in a country where attacks by Islamist militants have left hundreds of security personnel dead over the past 11 months.
The militants have stepped up attacks in response to the state's crackdown on Morsi's Muslim Brotherhood and its allies, in which more than 1,400 people have been killed and
President Pranab Mukherjee and Prime Minister Narendra Modi had sent congratulatory messages to Sisi after his successful election.
Modi in his message said that he was “confident that under your able leadership, Egypt will witness a new era of stability and prosperity," and that he "looked forward to working closely with you to further strengthen and expand our relations in the years ahead to fulfill the aspirations of our peoples".
Sisi, 59, was declared the country's President last week after winning 96.6 percent of the presidential vote, almost a year since the ouster of Islamist leader Mohamed Morsi last year.