The historic event was held at the International Conference Centre, Abuja, and attended by virtually all chieftains of the incoming ruling party, the All Progressives Congress, APC.
Speaking shortly after receiving the certificate, Buhari said he was humbled that Nigerians have chosen him to be Nigeria's next president.
According to him, "This is not a victory for me or the party; it is a victory for all Nigerians."
He said history has been made and "the change has finally come".
He pledged further, "My team and I shall faithfully serve you.
"We shall never rule over the people.
"There should be no wide jubilation but to reflect.
'Your labour will never be in vain.
"Democracy and rule of law shall prevail.
We must forget our past grievances and move ahead.
"Our government will listen and there shall be no favouritism.
"I pledge myself and my government to the rule of law.
"We shall never take you for granted.
"You shall be able to go to bed knowing that you are safe.
"You are all my people and I shall treat all of you as my own.
"We will govern for you and in your interest.
"I extend my hands of fellowship to President Jonathan and his team.
"Let me state clearly that President Jonathan has nothing to fear".
The President-Elect promised to fight corruption and wipe out insurgency in the land.
He thanked all the former Presidents of Nigeria, the leadership of the party and members but singled out APC leader, Bola Ahmed Tinubu, Bisi Akande and national chairman, John Odigie Oyegun for commendation.
Buhari also thanked President Barrack Obama and others world leaders who spoke out when it matters.
In his remarks earlier, the chairman of INEC, Prof Jega, thanked all Nigerians and stakeholders who made the presidential and National Assembly election a success.
He therefore, called on all to remain committed during the next governorship and state legislative election billed for April 11