The 40-year-old replaces Dean Holdsworth, who was sacked after two years in charge, and will be in the dugout for Saturday's npower League Two clash with Fleetwood after signing a deal until the end of the 2013-14 season.
He will be assisted by Terry Bullivant, who undertook the same role during their spell at Brentford, which included a title-winning campaign in the fourth tier.
A statement on the Shots' official website read: "Aldershot Town Football Club are delighted to announce the appointment of Andy Scott and Terry Bullivant as manager and assistant manager respectively on a contract until the end of the 2013-14 season.
"Having drawn up a shortlist of credible candidates since the departure of Dean Holdsworth, the board of directors felt that the experienced team of Andy and Terry offered the football club a real opportunity of making progress in the immediate and longer term."
The pair were sacked after three years at Griffin Park and Scott moved to Rotherham but was dismissed in March 2012 after spending less than a year in the job.
They join the Shots with the club, who were promoted to the Football League in 2008, sitting just two points above the drop zone after a run of one win in seven league games.
- Sports & Recreation
- Terry Bullivant
- Dean Holdsworth