Daniel Jenifer was born in Charles County, Maryland. He was a nephew of Daniel of St. Thomas Jenifer (1723-1790), one of the signers of the U.S. Constitution, and the son-in-law of Congressman John Campbell (1765-1828). He attended public schools and then studied law. In the early 1830s, he began a political career as a member of the short-lived National Republican Party. After the dissolution of his party in the mid-1830s, he became a member of the Whigs.
In the congressional elections of 1830, Jenifer was elected in the first constituency of Maryland in the U.S. House of Representatives in Washington, DC, where he succeeded on 4 March 1831, the successor to Clement Dorsey. Since he was not re-elected in 1832, he was initially only able to complete one term in Congress until March 3, 1833. This was marked by discussions about the policies of President Andrew Jackson. In these years, the Nullification Crisis reached its peak with the state of South Carolina. In 1834, Jenifer was re-elected to Congress in the seventh district of his state, where he was able to complete three more legislative periods between March 4, 1835, and March 3, 1841. There he experienced until 1837 the final phase of the term of President Jackson.
After the end of his time in the US House of Representatives Daniel Jenifer was appointed by President John Tyler as successor to Henry Muhlenberg, the ambassador to Vienna. In this capacity, he served until 1845, at which time he was replaced by the former congressman from Georgia, William Henry Stiles. Between 1845 and 1851, Daniel Jenifer was a notary for wills in Charles County. He died on December 18, 1855, near Port Tobacco Village.