India will also have the world's largest Facebook population by 2016, research firm eMarketer found.
India, with the highest growth this year, will increase user numbers by 37.4 percent, while Indonesia's numbers will climb 28.7 percent and Mexico will grow its social network user base by 21.1 percent.
All three of those countries are also high-growth areas for Facebook, the world's largest social network, which eMarketer estimates will reach a worldwide monthly user base of 1.026 billion this year.
The US remains the single country with the greatest number of Facebook users, at 146.8 million this year, and India comes in a distant second.
But with India's large population and high expected growth rate, eMarketer believes the country will develop the largest Facebook population of any country in the world by 2016.
Since Facebook is banned in China, eMarketer assumes there are no users of the social network in the country.
Growth in the number of social network users around the world may be slowing, but it shows little sign of stopping, based on eMarketer's latest forecast of Internet, broadband and social network users worldwide.
This year, eMarketer estimates, 1.61 billion people will log in to social networking sites at least monthly, from any electronic device.
That is a 14.2 percent gain on social networker numbers from 2012, and double-digit growth is expected to continue for another year. By 2017, 2.33 billion people will use social networks, the research found.
Currently, the highest penetration of social network users as a share of total population occurs in the Netherlands, where 63.5 percent of all residents are social network users; Norway follows just behind at 63.3 percent.
Majority of residents in Sweden, South Korea, Denmark, the US, Finland, Canada and the UK also use social networking sites monthly.
However, the fastest growth in social network usage is happening in "less-developed" markets.
For the study, eMarketer analysed quantitative and qualitative data from a variety of research firms, government agencies, media outlets and company reports.