The Republican Party of India (A) chief adopted the leopard, named as Bhima, a statement from his office said.
Athawale said he would bear all the expenses incurred on the upkeep of the wildcat in the park for next one year.
The Maharashtra forest department-run park, spread over 103 sq km and wedged between the suburbs of Mumbai and Thane, started an adoption scheme a few years ago due to rising maintenance cost of the animals.
The 57-year-old MP was once associated with the Dalit Panther movement, founded by late activist and poet Namdev Dhasal.