Henry W. Blair (1834–1920) was a U.S. Senator from New Hampshire from 1879 to 1891.
Senator Blair may also refer to:
Austin Blair (1818–1894), Michigan State Senate Craig Blair (born 1959), West Virginia State Senate Francis Preston Blair Jr. (1821–1875), Missouri State Senate H. S. Blair (1851–1932), Oklahoma State Senate John Blair (Tennessee politician) (1790–1863), Tennessee State Senate William Blair (American politician) (1820–1880), Wisconsin State Senate