| Election Name: | 1877 Iowa Senate election |
| Country: | Iowa |
| Flag Image: | Flag of Iowa (variant).svg |
| Type: | legislative |
| Ongoing: | no |
| Previous Election: | 1875 Iowa Senate election |
| Previous Year: | 1875 |
| Next Election: | 1879 Iowa Senate election |
| Next Year: | 1879 |
| Seats For Election: | 24 out of 50 seats in the Iowa State Senate |
| Majority Seats: | 26 |
| Election Date: | October 9, 1877 |
| Party1: | Republican Party (United States) |
| Last Election1: | 40 |
| Seat Change1: | 2 |
| Seats After1: | 38 |
| Party2: | Democratic Party (United States) |
| Last Election2: | 10 |
| Seat Change2: | 2 |
| Seats After2: | 12 |
In the 1877 Iowa State Senate elections, Iowa voters elected state senators to serve in the seventeenth Iowa General Assembly. Elections were held in 24 of the state senate's 50 districts. State senators serve four-year terms in the Iowa State Senate.
The general election took place on October 9, 1877.[1]
Following the previous election, Republicans had control of the Iowa Senate with 40 seats to Democrats' 10 seats.
To claim control of the chamber from Republicans, the Democrats needed to net 16 Senate seats.
Republicans maintained control of the Iowa State Senate following the 1877 general election with the balance of power shifting to Republicans holding 38 seats and Democrats having 12 seats (a net gain of 2 seats for Democrats).
| Senate District | Incumbent | Party | Elected Senator | Party | Outcome | |||
|---|---|---|---|---|---|---|---|---|
| 1st | Henry W. Rothert | Rep | James Madison Shelley | Dem | Dem Gain | |||
| 2nd | James Blakeny Pease | Dem | Horatio A. Wonn | Dem | Dem Hold | |||
| 3rd | Horatio A. Wonn | Dem | Joshua Miller | Rep | Rep Gain | |||
| 4th | Joshua Miller | Rep | Henry Laurens Dashiell | Rep | Rep Hold | |||
| 5th | Henry Laurens Dashiell | Rep | Samuel L. Bestow | Rep | Rep Hold | |||
| 6th | Samuel L. Bestow | Rep | Frederick Joseph Teale | Rep | Rep Hold | |||
| 7th | Frederick Joseph Teale | Rep | Philip W. Lewellen | Rep | Rep Hold | |||
| 9th | George Franklin Wright | Rep | John Patterson | Rep | Rep Hold | |||
| 10th | John Wilson Williams | Rep | John Simson Woolson | Rep | Rep Hold | |||
| 11th | John Simson Woolson | Rep | Moses Ayres McCoid | Rep | Rep Hold | |||
| 12th | Moses Ayres McCoid | Rep | Sanford S. Harned | Dem | Dem Gain | |||
| 13th | Joseph Henry Merrill | Rep | Gregg A. Madison | Dem | Dem Gain | |||
| 14th | Hosea N. Newton | Rep | William Wilson | Dem | Dem Gain | |||
| 15th | William Wilson | Dem | Thomas R. Gilmore | Rep | Rep Gain | |||
| 16th | Henry Thornburgh | Rep | John L. McCormack | Dem | Dem Gain | |||
| 17th | Lafayette Young | Rep | William Graham | Rep | Rep Hold | |||
| 18th | Thomas R. Gilmore | Rep | Lafayette Young | Rep | Rep Hold | |||
| 19th | John L. McCormack | Dem | George Franklin Wright | Rep | Rep Gain | |||
| 20th | William Graham | Rep | Thomas Hanna | Rep | Rep Hold | |||
| 21st | Gilbert H. Wood | Rep | William A. Foster | Rep | Rep Hold | |||
| 22nd | Jeremiah Henry Murphy | Dem | Nathaniel Anson Merrell | Dem | Dem Hold | |||
| 23rd | Nathaniel Anson Merrell | Dem | Henry C. Carr | Rep | Rep Gain | |||
| 24th | Henry C. Carr | Rep | William A. Maginnis | Dem | Dem Gain | |||
| 27th | Frank T. Campbell | Rep | Stephen Leland Dows | Rep | Rep Hold | |||
| 28th | Thomas Mitchell | Rep | John David Nichols | Rep | Rep Hold | |||
| 29th | Elias Jessup | Rep | John Meyer | Rep | Rep Hold | |||
| 30th | William A. Maginnis | Dem | Robert C. Webb | Rep | Rep Gain | |||
| 31st | George W. Lovell | Dem | Samuel D. Nichols | Rep | Rep Gain | |||
| 32nd | Stephen Leland Dows | Rep | Delos Arnold | Rep | Rep Hold | |||
| 33rd | John Shane | Rep | William Harrison Gallup | Rep | Rep Hold | |||
| 34th | Delos Arnold | Rep | Augustin W. Ford | Rep | Rep Hold | |||
| 35th | Dennis Nelson Cooley | Rep | Moses M. Ham | Dem | Dem Gain | |||
| 36th | Lewis Greenleaf Hersey | Rep | Charles E. Bronson | Dem | Dem Gain | |||
| 37th | Merritt W. Harmon | Rep | Daniel Darrow Chase | Rep | Rep Hold | |||
| 38th | John Conaway | Rep | Herman C. Hemenway | Rep | Rep Hold | |||
| 39th | John Thompson Stoneman | Dem | Merritt W. Harmon | Rep | Rep Gain | |||
| 40th | William Larrabee | Rep | John Thompson Stoneman | Dem | Dem Gain | |||
| 42nd | George R. Willett | Rep | Martin Nelson Johnson | Rep | Rep Hold | |||
| 43rd | Arad Hitchcock | Rep | William Larrabee | Rep | Rep Hold | |||
| 44th | Edward Gee Miller | Rep | Aaron Kimball | Rep | Rep Hold | |||
| 45th | William Harrison Gallup | Rep | Robert M. Haines | Rep | Rep Hold | |||
| 46th | Lemuel Dwelle | Rep | William Wallace Blackman | Rep | Rep Hold | |||
| 47th | Elden J. Hartshorn | Rep | Lemuel Dwelle | Rep | Rep Hold | |||
| 48th | Hiram Bailey | Rep | John J. Russell | Rep | Rep Hold | |||
| 49th | Samuel D. Nichols | Rep | Elden J. Hartshorn | Rep | Rep Hold | |||
| 50th | George Douglas Perkins | Rep | Albert Henry Lawrence | Rep | Rep Hold | |||
District boundaries in the Iowa Senate were redrawn before the 1877 general election.