Members unanimously agreed to demand immediate cross-border aid be allowed into all parts of the conflict-ravaged Middle East country to assist an estimated nine million people in desperate need.
The resolution also threatened “further steps” in the case of non-compliance, and condemned human rights abuses by both Syrian government forces and rebel groups.
Russia and China, until now strong supporters of president Bashar al-Assad, joined the rest of the council in sending a strong message to his government that civilians caught in the three-year conflict must be helped.
The resolution stopped short of threatening sanctions, which could have hindered aid efforts, but did call for an end to attacks on non-combatants.
Speaking after the vote UN Secretary-General Ban Ki-moon said the resolution should never “have been necessary”.
He said: “Humanitarian assistance is not something to be negotiated; it is something to be allowed by virtue of international law.
“Profoundly shocking to me is that both sides are besieging civilians as a tactic of war.”
The resolution will be examined after 30 days to ensure aid is getting through and that its terms are being upheld by all parties.
It is believed some 9.3 million people need help and that more than 140,000 Syrians have been killed in the civil war so far.
Since the start of February some 400 civilians are believed to have been killed in the northern city of Aleppo alone by Assad’s forces using crude barrel bombs.
The Syrian Observatory of Human Rights said shelling of civilian areas in the devastated city has intensified following a period of bad weather.
Despite the strongly worded resolution, many on the rebel side and further afield are sceptical that it will halt the shelling.
The historic resolution demands “that all parties, in particular the Syrian authorities, promptly allow rapid, safe and unhindered humanitarian access for UN humanitarian agencies and their implementing partners, including across conflict lines and across borders”.
It also “demands that all parties immediately cease all attacks against civilians, as well as the indiscriminate employment of weapons in populated areas, including shelling and aerial bombardment, such as the use of barrel bombs, and methods of warfare which are of a nature to cause superfluous injury or unnecessary suffering”.
Western members of the Security Council had been calling for a humanitarian resolution for almost a year.
UN aid chief Valerie Amos – a Labour peer – is one of the key movers behind yesterday’s vote.
She urged the Security Council to act after aid deliveries slowed to a trickle and said after the vote: “I hope the passing of a humanitarian resolution will facilitate the delivery of aid to people in desperate need. It is also vital that ordinary people, who have been bearing the brunt of the violence, are protected. More than anything the conflict needs to end so that people can begin to rebuild their lives.
“Syria is in danger of losing a generation of its children. Children are the future. We must protect them.”
Save the Children’s chief executive Justin Forsyth added: “We strongly welcome this UN resolution.”