Hewett finished the season as world number one after winning his third Wheelchair Tennis Masters singles title.
After going into the event second in the rankings, the 25-year-old defeated Argentina’s Gustavo Fernandez 4-6 6-1 6-3.
According to Hewett, topping the rankings was one of his goals.
“When I sat down at the beginning of the year I said I wanted to finish the year as number one.”
Hewett also won the doubles final on Saturday with fellow Briton Gordon Reid.
Their third Masters title came after they rallied from a set and 2-0 down against Fernandez and Martin de la Puente, the defending champions, to win 10-6 in a championship tie-break.
Hewett also won his third Masters singles title after wins in 2017 and 2021, and his seventh singles title overall.
“I’m obviously super happy,” he added.
“To be able to say we did it is something I’m extremely proud of – and to win the Masters singles title at the same time is an even more special feeling.”