Daniel F. Steck (December 16, 1881-December 31, 1950), was a member of the United States Senate.
Steck, a Democrat, appeared to have lost the 1924 race for Iowa's Senate seat against Smith W. Brookhart by a small margin, with Brookhart getting 447,594 votes to Steck's 446,840. Brookhart took office on March 4, 1925 and served until April 12, 1926 when the Senate voted by a margin of 45 to 41 to unseat Brookhart. Steck then took over the seat and served out the remainder of the term. On other occasions the Senate has settled election disputes before a Senator took office, but this is the only time the results were overturned after the Senator was seated.
When he took office in 1926, Steck became Iowa's first Democratic Senator since George W. Jones left office in 1859. Steck was unsuccessful in his reelection campaign of 1930.