"Or, at least, New Zealand," he said.
Named Mou Very - Japanese for nothing and French for soft - the bar is set to become Dunedin's latest tourist attraction, he said.
"It adds a bit of life to the city."
Mr Lequeux said 15 people were able to stand inside the 1.5m by 8m bar after it opened last week, and "they could breathe".
The venue has al fresco dining (in the alleyway) and kitchen (sandwich maker).
The restroom is outside toilets.
There were many advantages to having a smaller venue, he said.
"It makes everyone feel more comfortable.
"And I can also save on staff costs."
Mr Lequeux began roasting coffee out of the former George St jewellery site nearly three years ago.
"One day I just thought it would be a good bar."
The title of smallest "pub" in the world is believed to belong to a former railway signal box called the Signal Box Inn at Cleesthorpes, England.
The Signal Box Inn is just 2.4m by 2.4m.
