| Jehu Baker | |
| Office: | Member of the U.S. House of Representatives from Illinois |
| Term Start: | March 4, 1865 |
| Term End: | March 3, 1869 |
| Predecessor: | William Ralls Morrison |
| Successor: | John B. Hay |
| Term Start1: | March 4, 1887 |
| Term End1: | March 3, 1889 |
| Predecessor1: | William Ralls Morrison |
| Successor1: | William St. John Forman |
| Term Start2: | March 4, 1897 |
| Term End2: | March 3, 1899 |
| Predecessor2: | Everett J. Murphy |
| Successor2: | William A. Rodenberg |
| Office3: | United States Minister to Venezuela |
| President3: | Rutherford B. Hayes James A. Garfield |
| Term Start3: | March 18, 1878 |
| Term End3: | September 5, 1881 |
| Predecessor3: | Thomas Russell |
| Successor3: | George W. Carter |
| President4: | Chester A. Arthur Grover Cleveland |
| Term Start4: | May 16, 1882 |
| Term End4: | June 20, 1885 |
| Predecessor4: | George W. Carter |
| Successor4: | Charles L. Scott |
| Birth Date: | 4 November 1822 |
| Birth Place: | Lexington, Kentucky |
| Death Place: | Belleville, Illinois |
| Party: | Republican |
Jehu Baker (November 4, 1822 – March 1, 1903) was a U.S. Representative from Illinois.
Born near Lexington, Kentucky, Baker moved with his father to Lebanon, Illinois, in 1829. He attended the common schools and McKendree University. He studied law and was admitted to the bar in 1846, entering private practice in Belleville, Illinois. He served as master in chancery of St. Clair County, Illinois from 1861-1865.
Baker was elected as a Republican to the Thirty-ninth and Fortieth Congresses (March 4, 1865 – March 3, 1869), defeating incumbent William R. Morrison. He served as chairman of the Committee on Expenditures in the Post Office Department (Thirty-ninth Congress), Committee on Education and Labor (Fortieth Congress). In 1876, he campaigned in Illinois for Rutherford B. Hayes, who rewarded him by appointing him as United States Minister to Venezuela (1878–1881 and 1882–1885).
Baker was elected also as a Republican to the Fiftieth Congress (March 4, 1887 – March 3, 1889). He was an unsuccessful candidate for reelection in 1888 to the Fifty-first Congress. He continued the practice of law.
He later switched parties and was elected as a Democrat to the Fifty-fifth Congress (March 4, 1897 – March 3, 1899). He declined to be a candidate for renomination in 1898 to the Fifty-sixth Congress. He resumed the practice of law. He died in Belleville on March 1, 1903, and was buried in Walnut Hill Cemetery.