The centre-left party announced on Sunday that it would form a coalition with Angela Merkel's conservatives, giving the Chancellor her fourth term in office
Five months after an inconclusive election, Germany is finally to get a new government.
The centre-left Social Democrats (SPD) announced on Sunday that, in a postal vote, two thirds of members had backed entering a grand coalition with Chancellor Angela Merkel's conservatives.
The vote clears the way for a re-run of the 'grand coalition' that has governed Germany since 2013.
Merkel could be sworn in for her fourth term by mid-March.
On her Christian Democrats' (CDU) Twitter feed, she congratulated the SPD on the outcome of the vote.
"I congratulate the SPD on this clear result and look forward to continuing to work together for the good of our country," Merkel said.
Her junior partners are set to be led by another woman.
Former labour minister Andrea Nahles is likely to be chosen as SPD leader in April after Martin Schulz stepped down to try to end turmoil in the party since it agreed the coalition deal.