Rufus Ranney was born on October 30, 1813, at Blandford, Massachusetts. In 1822, his family moved to Portage County, Ohio. Self educated, Ranney eventually enrolled in Western Reserve College. He earned tuition by chopping wood, but he eventually left the institution because he lacked enough funds to cover his expenses. In 1834, he began to study law, passing the bar exam in 1836.
Ranney was a devoted member of the Democratic Party, and he ran for the United States House of Representatives in 1846 and again in 1848. He lost both elections, although Trumbull County residents selected Ranney to represent them at the Ohio Constitutional Convention of 1850-1851. At the convention, Ranney supported popular election of state judges, but he opposed granting the governor the power to veto.
In 1851, the Ohio legislature appointed Ranney to the Ohio Supreme Court. All future justices were elected by the eligible voters. After the adoption of the Constitution of 1851, Ohio voters elected Ranney to the Supreme Court. Ranney's term began in 1852 and was to end in 1857, but he resigned in 1856. He then established a law practice in Cleveland, Ohio. Ranney did not remain out of politics for long. In 1859, he was the Democratic Party's nominee for Ohio governor. Ranney lost the election to William Dennison by thirteen thousand votes. Democratic Party officials hoped that Ranney's anti-slavery views would attract voters away from the Republican Party, but their plan failed to secure Ranney the election. In 1862, the Democratic Party nominated Ranney to serve on the Ohio Supreme Court once again. Although Ranney wished to remain in private practice, he won the election and served as a justice from 1863 to 1865, when he again resigned to resume his private legal career.
Ranney was one of the most respected attorneys in Ohio during this time period. When the Ohio State Bar Association was formed in 1881, members unanimously elected him the group's first president. He withdrew from private practice in his later years. Ranney died on December 6, 1891, in Cleveland.