"The Secretary-General is seriously concerned by the military takeover in Thailand today. He appeals for a prompt return to constitutional, civilian, democratic rule and an all-inclusive dialogue that will pave the way for long-term peace and prosperity in Thailand," a statement issued by Ban's spokesman said.
The Thai military today staged a coup, taking full control of the country just two days after declaring martial law.
The coup was announced on national television by Thailand's head of the army General Prayuth Chan-O-Cha who said it was "necessary to seize power".
Ban urged all parties to work together constructively, refrain from violence and respect human rights.
This is the second time in eight years that the military has taken over in Thailand.
The last coup was in 2006 and was followed by more than a year of military rule.