An official in the Serbian deputy prime minister's office said more details about his new position should be available Tuesday, CNN reported.
Strauss-Kahn, 64, is not expected to move to Serbia, the official said, but will come to the country "from time to time."
He was chosen, the official said, "because he is an expert in the field of economics."
Strauss-Kahn resigned his post with the IMF in 2011 after he was charged with sexually assaulting a maid at a New York City hotel. The charges were later dropped.
He recently advised the government of South Sudan.