The service was held in the largest Catholic church in the US.
Antonin Scalia’s coffin had earlier lain in the Supreme Court with President Barack Obama among those paying respects.
The death of Antonin Scalia, who was seen as a hero by the US right, has sparked a political row over his successor.
Thousands of people filled the vast Basilica of the National Shrine of the Immaculate Conception on February 20.
One of Antonin Scalia’s nine children, Rev Paul Scalia, led the Mass, ahead of a private burial.
Rev. Paul Scalia, who serves the diocese of Arlington, Virginia, said: “We are gathered here because of one man. A man known personally to many of us, known only by reputation to even more, a man loved by many, scorned by others, a man known for great controversy, and for great compassion.”
He then added: “That man, of course, is Jesus of Nazareth.”
It was because of Jesus that “in confidence we commend Antonin Scalia to the mercy of God”.
The country’s eight remaining Supreme Court justices attended the service.
One of them, Clarence Thomas, offered a Bible reading.
The Supreme Court says more than 6,000 visitors viewed the casket in the Great Hall on February 19.
President Barack Obama and First Lady Michelle Obama were among those paying their respects at the flag-draped coffin, but were not at the funeral.
VP Joe Biden was at the Mass – he has a close personal relationship with the Scalia family – as was Republican presidential hopeful Ted Cruz.
White House spokesman Josh Earnest said Barack Obama’s attendance could have created security issues.
Ted Cruz has been among those demanding there be no nomination of a successor until after the November presidential election.
Barack Obama has insisted he will go through with the nomination.
Antonin Scalia’s death leaves the Supreme Court evenly divided between liberal and conservative justices ahead of crucial cases on abortion, voting rights and immigration.
According to the constitution, the president nominates justices to the court and the Senate uses its “advice and consent” powers to confirm or reject that person.
Antonin Scalia died unexpectedly at his remote Texas ranch on February 13.
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