The award follows discussions between the Inverclyde council, the Scottish Government and local umbrella organisation Cosla.
Councillor Jim Clocherty, Inverclyde's Depute Council Leader, said: "For the past few years we have made identifying, planning and dealing with flooding a priority and it is fantastic that we have now secured the funding to press ahead and make a real difference."
The council had previously applied for a share of funding in April, but failed in its bid after the Scottish Government said the issue didn't meet the criteria for a major protection project.
Now following ongoing dialogue it has been agreed that the Greenock element of the Inverclyde Flood Protection Scheme - composed of a number of hydraulically-linked parts - comprises a single project and meets conditions set out by the funding scheme.
In recent years Inverclyde has suffered many severe floods, with roads, railways and town centres affected.