The 31-year-old singer has signed a two-year deal for a concert residency in the US gambling capital.
Spears' contract states she will perform 48 shows a year, earning her a total of USD 14,880,000.
The 'Gimme More' singer's income comes from share of ticket sales at the PH Live auditorium - which holds 4,500 people.
Spears, who has two sons, Sean Preston, seven, and Jayden James, six, was at the centre of a bidding war between several Las Vegas hotels earlier this year, with many top chains hoping to land her services for a residency before Planet Hollywood emerged as the venue for her shows.