The takeover comes just a few months after SAC pulled out of a proposed deal with League Two side Colchester United following a period of discussions.
Northampton confirmed the news that SAC had taken over, a consortium which includes former AC Milan, Chelsea and Brazil forward Pato, who is an investor and board member.
As per the BBC, existing owners David Bower, Nigel Le Quesne and Kelvin Thomas will collectively retain a 30% shareholding whilst SAC's Joao Xavier and Tim Chamberlain will become co-chairmen.
A new era for Northampton
In a joint statement, Xavier and Chamberlain revealed they were "extremely proud to become custodians of a club with such a rich history, passionate supporter base and important place within its community".
"We have ambitious plans for Northampton Town, but ambition must go hand in hand with sustainability and an understanding of what the club means to the people of Northampton and Northamptonshire," the statement added.
"We want the club to continue to be a source of pride within its community and will work closely with the Community Trust, supporters, staff, partners and local stakeholders to ensure that relationship continues to grow.
"We are looking forward to spending much more time in Northampton, listening to supporters and working together to help the club realise its potential both on and off the pitch.
"This is the beginning of a long-term commitment from Sports Alpha Capital to Northampton Town Football Club, and we are incredibly excited about the journey ahead."
The club also stated: "Further details regarding Sports Alpha Capital, the new Board and the future plans for Northampton Town Football Club will follow."
Northampton will next face Cambridge United in the EFL Trophy next week as they enter a new era.