The Athletic and The New York Times reported Leonard is signing a three-year, $103 million max contract. The contract has a player option in the third season and would allow him to become a free agent after the 2020-21 season.
New Clippers teammate Paul George can potentially be a free agent after the 2020-21 season. George has a $37.8 million player option for the 2012-22 season.
George has two-non option years and $68 million remaining on his contract. Los Angeles acquired George in a trade with the Oklahoma City Thunder last week.
Leonard would be eligible for another max contract in two seasons when he reaches 10 years of service. He was the No. 15 overall pick in the 2011 NBA Draft from San Diego State University.
Leonard averaged 26.6 points and 7.3 rebounds in his lone season with the Toronto Raptors last year. He added 30.5 points and 9.1 rebounds in 24 playoff games as the Raptors won their first NBA title.
The 28-year-old is a three-time NBA All-Star and two-time NBA Defensive Player of the Year.
The Clippers went 48-34 last season before losing to the Golden State Warriors in the Western Conference Quarterfinals.