John Southgate Tucker was born on May 31, 1838 in Norfolk, Virginia, where his family on both sides had been prominent since before the American Revolution. He attended the Episcopal School in Alexandria, Virginia and entered Dickinson College in Carlisle, Pennsylvania in 1853 and joined the class of 1855. While at Dickinson, he was elected as a member of the Belles Lettres Society and also became one of the notorious founder members of the Phi Kappa Sigma fraternity. He graduated with his class in the early summer of 1855 and studied for the law.

For a time he was editor of the Norfolk Virginia newspaper and practiced law in the city. At the outbreak of the Civil War he joined the army of the Confederate States and rose to the rank of captain of artillery. Returning home to Norfolk, he served as city attorney between 1866 and 1868; he was the Mayor of Norfolk from 1876 to 1880. As mayor, he was instrumental in persuading a reluctant city council to build a new public school for African-Americans to replace the dilapidated Bute Street School. Later he was a member on nearby Yorktown's centennial commission celebrating the anniversary of the British defeat there. He also worked as federally appointed examiner of land claims at the main United States Land Office in Washington D.C..

Tucker married Mary Irwin in 1868. Following Mary's death he married a second time, to Bessie C. Chubb. John Southgate Tucker died on May 19, 1920 twelve days before his eighty-second birthday. He is buried in St. Paul's Churchyard in Norfolk.