Yonetaro Otani, a former sumo wrestler who founded and ran a small steel company, agreed to build the hotel on a site he owned.

[2] The 1,085-room hotel was built in seventeen months using a number of techniques that were revolutionary in Japan at the time, such as curtain walls and prefabricated unit bathrooms.

[3] However, by the time of its completion, the arrangement was no longer in place,[a] and the hotel opened as The New Otani on 1 September 1964, to coincide with the Olympics the following month.

[4] The original 1964 building, today referred to as "The Main", was extensively renovated and remodelled in 2007, when it was given a modern glass facade.

The hotel assumed operation of the Akasaka Palace, the Japanese State Guest House, in 1976.