Senator O'Brien

Senator O'Brien may refer to:


 * Anna Belle Clement O'Brien (1923–2009), Tennessee State Senate
 * Charles H. O'Brien (1920–2007), Tennessee State Senate
 * Duncan T. O'Brien (1895–1938), New York State Senate
 * Henry L. O'Brien (1869–1935), New York State Senate
 * James H. O'Brien (1860–1924), New York State Senate
 * James O'Brien (U.S. Congressman) (1841–1907), New York State Senate
 * Jay O'Brien (Virginia politician) (born 1951), Virginia State Senate
 * Jeremiah O'Brien (Maine politician) (1778–1858), Maine State Senate
 * Leo P. O'Brien (1893–1968), Wisconsin State Senate
 * Margaret O'Brien (politician) (born 1973), Michigan State Senate
 * Sean O'Brien (Ohio politician) (born 1969), Ohio State Senate
 * Shannon O'Brien (born 1959), Massachusetts State Senate
 * Ted O'Brien (born 1956), New York State Senate