| | Year | | Senator | | Party | | State | | Reason |
| a href="/encyclopedia/1811" title="1811">1811 | Timothy Pickering | Federalist | Massachusetts | Reading confidential documents in open Senate session before an injunction of secrecy was removed. |
| a href="/encyclopedia/1844" title="1844">1844 | Benjamin Tappan | Democrat | Ohio | Releasing to the New York Evening Post a copy of President John Tyler's message to the Senate regarding the treaty of annexation between the United States and the Republic of Texas. |
| a href="/encyclopedia/1902" title="1902">1902 | Benjamin R. Tillman | Democrat | South Carolina | Fighting on the Senate floor with John L. McLaurin. |
| a href="/encyclopedia/1902" title="1902">1902 | John L. McLaurin | Democrat | South Carolina | Fighting on the Senate floor with Benjamin R. Tillman. |
| a href="/encyclopedia/1929" title="1929">1929 | Hiram Bingham | Republican | Connecticut | Employing as a Senate staff member Charles Eyanson, who was simultaneously employed by the Manufacturers Association of Connecticut. |
| a href="/encyclopedia/1954" title="1954">1954 | Joseph R. McCarthy | Republican | Wisconsin | Abuse and non-cooperation with the Subcommittee on Privileges and Elections during a 1952 investigation of his conduct; for abuse of the Select Committee to Study Censure. |
| a href="/encyclopedia/1967" title="1967">1967 | Thomas J. Dodd | Democrat | Connecticut | Use of his office to convert campaign funds to his personal benefit. Conduct unbecoming a senator. |
| a href="/encyclopedia/1979" title="1979">1979 | Herman E. Talmadge | Democrat | Georgia | Improper financial conduct, accepting reimbursements for official expenses not incurred, and improper reporting of campaign receipts and expenditures. |
| a href="/encyclopedia/1990" title="1990">1990 | David F. Durenberger | Republican | Minnesota | Unethical conduct relating to reimbursement of Senate expenses and acceptance of outside payments and gifts. |