"I congratulate Mr Donald Trump on his election as forty-fifth President of the United States of America," the UN Secretary-General said in a statement.
Ban said given the hard-fought and "often divisive campaign" to elect the new US President, it is "worth recalling and reaffirming that the unity in diversity of the United States is one of the country's greatest strengths. I encourage all Americans to stay true to that spirit."
"The United Nations will count on the new Administration to strengthen the bonds of international cooperation as we strive together to uphold shared ideals, combat climate change, advance human rights, promote mutual understanding and implement the Sustainable Development Goals to achieve lives of peace, prosperity and dignity for all," Ban said.
Ban underscored that as a founding-member of the UN and a permanent member of the Security Council, the US is an "essential actor" across the international agenda and people globally look to America to "use its remarkable power to help lift humanity up and to work for the common good."
The UN chief also expressed his "deep appreciation" to former Secretary of State Hillary Clinton for a "lifetime commitment to peace, the advancement of women and the well-being of children.
"She has been a powerful global symbol of women's empowerment, and I have no doubt that she will continue to contribute to our work across the world," he said.