<P> A total of 113 Justices have served on the Supreme Court of the United States , the highest judicial body in the United States . Justices have life tenure , and so they serve until they die in office , resign or retire , or are impeached and removed from office ( which has never happened ; the one impeached Justice was acquitted ) . The longest - serving member of the current court is Associate Justice Anthony Kennedy , with a term to date of 7004108520000000000 ♠ 10,852 days ( 29 years ) . For the 104 non-incumbent justices , the mean length of service was 6,112 days ( 16.7 years ) with a standard deviation of 3,620 days ( 9.9 years ) . The median length of service was 5,740 days ( 15.7 years ) . Their period of service ranges from William O. Douglas 's 13,358 days ( 36 years ) on the Court to the 163 - day tenure of Thomas Johnson . </P>
<P> A total of 113 Justices have served on the Supreme Court of the United States , the highest judicial body in the United States . Justices have life tenure , and so they serve until they die in office , resign or retire , or are impeached and removed from office ( which has never happened ; the one impeached Justice was acquitted ) . The longest - serving member of the current court is Associate Justice Anthony Kennedy , with a term to date of 7004108520000000000 ♠ 10,852 days ( 29 years ) . For the 104 non-incumbent justices , the mean length of service was 6,112 days ( 16.7 years ) with a standard deviation of 3,620 days ( 9.9 years ) . The median length of service was 5,740 days ( 15.7 years ) . Their period of service ranges from William O. Douglas 's 13,358 days ( 36 years ) on the Court to the 163 - day tenure of Thomas Johnson . </P>
who is currently the longest serving supreme court justice
who is currently the longest serving supreme court justice
Anthony Kennedy
Anthony Kennedy