The €2.8bn ($2.85bn) project will be one of the largest interconnector projects in the world, measuring 725km in length.
It reached financial close with a consortium of more than 20 international banks and financial institutions.
NeuConnect now expects to begin early works for the project later this year.
The project will link a substation in the Isle of Grain in Kent, England, with another at the Wilhelmshaven region in Lower Saxonia, northern Germany.
These two substations will be connected by subsea cables travelling through British, Dutch and German waters.
The high-voltage direct current link will enable the transmission of up to 1.4GW of electricity, which is enough to power 1.5 million homes.
NeuConnect Board chair and Meridiam co-founder Julia Prescot said: “NeuConnect will create a vital new energy link at a time when sustainable, resilient connections across Europe have never been more important.
“Delivering innovative, highly complex projects is in our DNA at Meridiam, so as NeuConnect’s lead investor, we are proud to reach financial close on one of the world’s largest interconnector projects – a significant milestone that brings the first direct energy link between the UK and Germany an important step closer.”
Major construction works on the NeuConnect project are expected to start next year, with operations scheduled to begin in 2028.
Once operational, the project will further secure energy supplies and help the UK and Germany achieve their net-zero goals.
NeuConnect recently awarded several key contracts related to the project, including £1.5bn ($1.95bn) worth of contracts given to Prysmian Group and Siemens Energy for cabling works and converter stations.