Justice Brett Kavanaugh has tested positive for Covid-19.
The Supreme Court said in a press release that Mr Kavanaugh tested positive on Thursday.
He has no symptoms and has been fully vaccinated since January.
Mr Kavanaugh and all the other justices had a routine coronavirus test ahead of Friday’s ceremonial investiture for Justice Amy Coney Barrett.
The court says Mr Kavanaugh’s wife and daughters are also fully vaccinated, and they tested negative on Thursday.
Mr Kavanaugh and his wife will not attend the ceremony.
On Wednesday, Mr Kavanaugh took part in the 3 mile ACLI Capital Challenge, an annual race held for members of Congress, judges and journalists.
Other competitors included Representatives Mike Gallagher, Kathleen Rice, and Senators Shelley Moore Capito, Kyrsten Sinema and John Cornyn.
Mr Kavanaugh came first in the male federal judges category in a time of 24 minutes 26 seconds.
The nine Supreme Court justices were due to hold their first in-person sessions at the start of the new term on Monday. It would have been the first time since before the pandemic that the justices returned to the courtroom.
Mr Kavanaugh was appointed to the Supreme Court by Donald Trump in 2018 after the retirement of Anthony Kennedy.
In June, he voted to leave in place a pandemic-inspired nationwide ban on evictions, siding with the three liberal justices and Chief Justice John Roberts in a 5-4 decision.
A White House Rose Garden ceremony in September 2018 to announce Ms Coney Barrett’s appointment to the court became a “superspreader event”.
Mr Trump, his wife Melania, former New Jersey Governor Chris Christie and White House counselor Kellyanne Conway all tested positive after the ceremony.
It was attended by more than 150 people, many of whom did not wear masks or practice social distancing.
