| Election Name: | Missouri Senate elections, 2018 |
| Country: | Missouri |
| Type: | legislative |
| Ongoing: | no |
| Previous Election: | Missouri Senate elections, 2016 |
| Previous Year: | 2016 |
| Next Election: | 2020 Missouri Senate election |
| Next Year: | 2020 |
| Seats For Election: | 17 of Missouri's 34 Senate seats in the Missouri Senate. |
| Image1: | File:Ron Richard.jpg |
| Leader1: | Ron Richard (retired) |
| Party1: | Republican Party (United States) |
| Leader Since1: | September 15, 2015 |
| Leaders Seat1: | 32nd district |
| Last Election1: | 24 |
| Seats1: | 24 |
| Popular Vote1: | 710,940 |
| Percentage1: | 58.59% |
| Leader2: | Gina Walsh |
| Party2: | Democratic Party (United States) |
| Leader Since2: | July 7, 2016 |
| Leaders Seat2: | 13th district |
| Last Election2: | 10 |
| Seats2: | 10 |
| Popular Vote2: | 494,965 |
| Percentage2: | 40.79% |
| Map Size: | 300px |
| President pro tempore | |
| Before Election: | Ron Richard |
| Before Party: | Republican Party (United States) |
| After Election: | Dave Schatz |
| After Party: | Republican Party (United States) |
The 2018 Missouri Senate elections were held on November 6, 2018, to elect the seventeen Missouri Senators to the Missouri Senate. Half of the Senate's thirty-four seats are up for election every two years, with each Senator serving four-year terms. The next time that these seats were up was in the 2022 Missouri Senate election.
| Party | Candi- dates | Votes | Seats | |||||
|---|---|---|---|---|---|---|---|---|
| No. | % | No. | +/– ! | % | ||||
| 16 | 710,940 | 58.59% | 14 | 82.35% | ||||
| 17 | 494,965 | 40.79% | 3 | 17.65% | ||||
| 3 | 5,279 | 0.44% | 0 | 0.00% | ||||
| 1 | 2,114 | 0.17% | 0 | 0.00% | ||||
| 1 | 28 | 0.00% | 0 | 0.00% | ||||
| Total | 38 | 1,213,326 | 100.00% | 17 | 100.00% | |||
Results of the 2018 Missouri State Senate elections by district:
| scope=col rowspan=3 | District | scope=col colspan=2 | Republican | scope=col colspan=2 | Democratic | scope=col colspan=2 | Others | scope=col colspan=2 | Total | scope=col rowspan=3 | Result | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| scope=col colspan=2 style="background:" | ! | scope=col colspan=2 style="background:" | ! | scope=col colspan=2 | ! | scope=col colspan=2 | |||||||||
| scope=col data-sort-type="number" | Votes ! | scope=col data-sort-type="number" | % ! | scope=col data-sort-type="number" | Votes ! | scope=col data-sort-type="number" | % ! | scope=col data-sort-type="number" | Votes ! | scope=col data-sort-type="number" | % ! | scope=col data-sort-type="number" | Votes ! | scope=col data-sort-type="number" | % |
| District 2 | 52,145 | 59.69% | 35,219 | 40.31% | - | - | 87,364 | 100.00% | Republican Hold | ||||||
| District 4 | 16,773 | 22.96% | 56,289 | 77.04% | - | - | 73,062 | 100.00% | Democratic Hold | ||||||
| District 6 | 52,861 | 73.22% | 17,783 | 24.63% | 1,548 | 2.15% | 72,192 | 100.00% | Republican Hold | ||||||
| District 8 | 41,094 | 54.69% | 34,052 | 45.31% | - | - | 75,146 | 100.00% | Republican Hold | ||||||
| District 10 | 48,277 | 70.31% | 20,384 | 29.69% | - | - | 68,661 | 100.00% | Republican Hold | ||||||
| District 12 | 49,947 | 72.50% | 18,950 | 27.50% | - | - | 68,897 | 100.00% | Republican Hold | ||||||
| District 14 | - | - | 51,815 | 100.00% | - | - | 51,815 | 100.00% | Democratic Hold | ||||||
| District 16 | 41,985 | 70.18% | 17,839 | 29.82% | - | - | 59,824 | 100.00% | Republican Hold | ||||||
| District 18 | 46,225 | 70.30% | 19,528 | 29.70% | - | - | 65,753 | 100.00% | Republican Hold | ||||||
| District 20 | 62,247 | 73.88% | 22,006 | 26.12% | - | - | 84,253 | 100.00% | Republican Hold | ||||||
| District 22 | 40,553 | 58.33% | 26,896 | 38.68% | 2,077 | 2.99% | 69,526 | 100.00% | Republican Hold | ||||||
| District 24 | 30,494 | 37.15% | 49,910 | 60.80% | 1,682 | 2.05% | 82,086 | 100.00% | Democratic Hold | ||||||
| District 26 | 53,143 | 64.02% | 29,866 | 35.98% | - | - | 83,009 | 100.00% | Republican Hold | ||||||
| District 28 | 53,659 | 79.18% | 14,113 | 20.82% | - | - | 67,772 | 100.00% | Republican Hold | ||||||
| District 30 | 34,506 | 53.35% | 30,175 | 46.65% | - | - | 64,681 | 100.00% | Republican Hold | ||||||
| District 32 | 48,383 | 73.73% | 15,125 | 23.05% | 2,114 | 3.22% | 65,622 | 100.00% | Republican Hold | ||||||
| District 34 | 38,648 | 52.47% | 35,015 | 47.53% | - | - | 73,663 | 100.00% | Republican Hold | ||||||
| Total | 710,940 | 58.59% | 494,965 | 40.79% | 7,421 | 0.61% | 1,213,326 | 100.00% |
Districts where the margin of victory was under 10%: