While most countries have one or a handful of official or nationally recognized languages, there are typically groups of people residing in each country whose first language is something other than the nation's lingua franca. The numbers of such groups differ from country to country, and the size of these minority language "groups" can range from a single individual to millions of speakers.
Papua New Guinea (PNG) takes the top spot with an overwhelming 820 languages. This diversity is largely explained by the country’s topography: deep valleys and unnavigable terrain separated hundreds of different clans for centuries, giving rise to distinct languages and customs.
The country has a relatively small population of seven million, which means it is incredibly likely that two randomly selected people will have different mother tongues.
Indonesia, PNG's close neighbor, is not so far behind with almost 750 languages. Below are the 20 countries where the most languages are spoken today, including all established and immigrant languages.
Source : Ethnologue.com