Ban congratulated Ibrahim Boubacar Keita on his election and commended the loser, Soumaila Cisse, for his "commitment to democratic values," the UN chief's spokesman Martin Nesirky said.
Cisse quickly conceded defeat in Sunday's second round ballot and said he would not challenge the result of the vote.
"The secretary general reiterates the commitment of the United Nations to accompany Mali in the next phase of its stabilisation and peace consolidation process, including by supporting inclusive dialogue and reconciliation and the conduct of the national legislative elections.
Official results, which must be confirmed by Mali's constitutional court, showed Keita winning by a landslide with 77.6 per cent of the votes against 22.3 per cent for Cisse.