John Quincy Adams II (September 22, 1833 – August 14, 1894) was an American lawyer and politician.
Adams was the son of Charles Francis Adams and Abigail Brown Brooks, the grandson and namesake of president John Quincy Adams and the great-grandson of President John Adams. He graduated from Harvard University in 1853, studied law, attained admission to the bar, and practiced in Boston. He later established an experimental model farm near Quincy, Massachusetts. Adams married Frances (Fanny) Cadwalader Crowninshield (1839–1911), daughter of George (1812–1857) and Harriet Sears Crowninshield (1809–1873) of the politically powerful Crowninshield family.
During the Civil War he served on the staff of Governor John Andrew with the rank of Colonel.
Adams served in several local offices in Quincy, including town meeting moderator, school board chairman and judge of the local court. He was elected to the Massachusetts state legislature as a Republican, but soon switched to the Democratic Party because of his disaffection with Republican Reconstruction policies. In addition to serving in the Massachusetts House of Representatives in 1865, 1867, 1870 and 1873, he was the unsuccessful Democratic nominee for Governor of Massachusetts every year from 1867 to 1871. In 1873 he was the unsuccessful nominee for lieutenant governor.
Adams received one vote for the Democratic nomination for President of the United States at the 1868 Democratic National Convention. In 1872 the faction of Democrats that refused to support Horace Greeley nominated Charles O'Conor for president and John Quincy Adams II for vice-president on the "straight Democratic" ticket. They declined, but their names remained on the ballot in some states. After losing an election for lieutenant governor in 1876, Adams refused most further involvement in politics, though he was considered by Grover Cleveland for a cabinet position in 1893.
In 1877 he was made a member of the Harvard Corporation. Adams died at age 60 in Quincy on August 24, 1894. He was buried at Mount Wollaston Cemetery in Quincy.
- George Caspar Adams (1863–1900)
- Charles Francis Adams III, United States Secretary of the Navy (1866–1954)
- Frances ("Fanny") C. Adams (1873–1876)
- Arthur Adams (1877–1943)
- Abigail ("Hitty") Adams (1879–1974)
- Browning, Charles Henry. Americans of Royal Descent: A Collection of Genealogies of American Families Whose Lineage is traced to the Legitimate Issue of Kings. Philadelphia: Porter & Costes, 1891, ed. 2, pp. 68 – 69.