MPs voted 307 to 173 against the proposed change to the Children’s Wellbeing and Schools Bill.
A ban on social media for under-16s has been rejected by MPs.
The age limit had been backed by peers earlier this year after growing calls from campaigners including actor Hugh Grant.
Supporters of the Australian-style ban said parents are in “an impossible position” over the online harms their children are being exposed to.
Others, including the NSPCC, warned a ban could drive teenagers into unregulated corners of the internet.
MPs voted 307 to 173, majority 134, against the proposed change to the Children’s Wellbeing and Schools Bill, which was brought forward by Conservative former minister Lord Nash.
However, a ban could still come in future after the Commons supported a Government bid to give additional powers to the Secretary of State.
