The petition, believed to be one of the largest ever compiled, calls for an immediate end to Transatlantic Trade and Investment Partnership (TTIP) negotiations.
Some 500,000 people in the UK signed the petition, alongside millions of EU citizens.
It cites concern over the lowering of environmental, consumer and employment protections and the deregulation of public services such as water as a result of TTIP.
Campaigners also highlight the controversial investor-state dispute settlement (ISDS), a clause that would pave the way for private firms to sue governments in cases where government policies threaten a company’s profits.
In March, a British parliamentary committee published a scathing attack on TTIP in which it called on the government to produce more convincing evidence in favor of the deal.
There are also fears powerful tobacco companies could use TTIP to sue governments that attempt to legislate in the public interest, according to heavily redacted European Commission documents released last month.