Despite opposition on the issue from countries including China, Russia and India, countries promoting the resolution hailed the support of dozens of nations ahead of its adoption.
"This outcome is momentous for the Human Rights Council," US ambassador Eileen Chamberlain Donahoe told reporters.
"It's the first UN resolution that confirms that human rights in the Internet realm must be protected with the same commitment as in the real world."
The text had the support of 85 co-sponsors, 30 of whom are members of the HRC, Donahoe added.
Of the states that supported the initiative, Tunisia's ambassador Moncef Baati said it was particularly important for his country because of the role accredited to social networking websites in ousting president Zine El Abidine Ben Ali in 2011.
"The most important result of the Tunisian revolution is this right to freedom of expression...(this) is very important at the moment (in Tunisia) and it is for this reason that there is a strong commitment in Tunisia to consolidate Internet rights.
"Our link with all media networks during the revolution doubles the importance of this commitment to freedom of expression on the Internet which remains a major tool for economic development."
Other countries that backed the resolution on the Promotion, Protection and Enjoyment of Human Rights on the Internet included Brazil, Nigeria, Sweden and Turkey.