| Year: | 2018 |
| Conference: | Missouri Valley Conference |
| Division: | I |
| Gender: | Men's |
| Teams: | 10 |
| Arena: | Scottrade Center |
| City: | St. Louis, Missouri |
| Champions: | Loyola–Chicago |
| Titlecount: | 1st |
| Coach: | Porter Moser |
| Coachcount: | 1st |
| Mvp: | Donte Ingram |
| Mvpteam: | Loyola–Chicago |
| Television: | CBS, CBSSN, MVC TV (ESPN3) |
The 2018 Missouri Valley Conference men's basketball tournament, popularly referred to as "Arch Madness", was the postseason men's basketball tournament that completed the 2017–18 season in the Missouri Valley Conference. The Tournament was held at the Scottrade Center, now known as the Enterprise Center, in St. Louis, Missouri from March 1–4, 2018.
The Tournament marked the first tournament with Valparaiso as a member of the MVC, having replaced Wichita State when the Shockers joined the American Athletic Conference in June 2017.
The tournament's top seed, Loyola–Chicago defeated the No. 3 seed Illinois State in the championship game to receive the Missouri Valley's automatic bid to the NCAA tournament.
Teams were seeded by conference record, with ties broken by overall record in conference games played between the tied teams, then (if necessary) by overall adjusted RPI on the day following the conclusion of the regular season as calculated in Collegiate Basketball News' Men's RPI Report. The top six seeds received opening round byes.
With a win at Southern Illinois on February 21, Loyola–Chicago clinched the outright MVC championship and the No. 1 seed.[1]
| Seed | School | Conference | Tiebreaker 1 | Tiebreaker 2 | |
|---|---|---|---|---|---|
| 1 | Loyola–Chicago | 15–3 | |||
| 2 | Southern Illinois | 11–7 | |||
| 3 | Illinois State | 10–8 | 1–1 vs. Drake | RPI: 84 | |
| 4 | Drake | 10–8 | 1–1 vs. Illinois St | RPI: 162 | |
| 5 | Bradley | 9–9 | |||
| 6 | Indiana State | 8–10 | |||
| 7 | Missouri State | 7–11 | 1–1 vs. Evansville, 1–1 vs. N. Iowa | RPI: 133 | |
| 8 | Evansville | 7–11 | 1–1 vs. Missouri St, 1–1 vs. N. Iowa | RPI: 137 | |
| 9 | Northern Iowa | 7–11 | 1–1 vs. Missouri St, 1–1 vs. Evansville | RPI: 141 | |
| 10 | Valparaiso | 6–12 |
| Game | Time * | Matchup | Score | Television | |
|---|---|---|---|---|---|
| Opening round – Thursday, March 1 | |||||
| 1 | 6:00 pm | No. 8 Evansville vs. No. 9 Northern Iowa | 50–60 | align=center rowspan=2 | MVC TV [ESPN3] |
| 2 | 8:30 pm | No. 7 Missouri State vs. No. 10 Valparaiso | 83–79 | ||
| Quarterfinals – Friday, March 2 | |||||
| 3 | 12:00 pm | No. 1 Loyola–Chicago vs. No. 9 Northern Iowa | 54–50 | align=center rowspan=4 | MVC TV [ESPN3] |
| 4 | 2:30 pm | No. 4 Drake vs. No. 5 Bradley | 61–63 | ||
| 5 | 6:00 pm | No. 2 Southern Illinois vs. No. 7 Missouri State | 67–63 | ||
| 6 | 8:30 pm | No. 3 Illinois State vs. No. 6 Indiana State | 77–70 | ||
| Semifinals – Saturday, March 3 | |||||
| 7 | 2:30 pm | No. 1 Loyola–Chicago vs. No. 5 Bradley | 62–54 | align=center rowspan=2 | CBSSN |
| 8 | 5:00 pm | No. 2 Southern Illinois vs. No. 3 Illinois State | 68–76 OT | ||
| Final – Sunday, March 4 | |||||
| 9 | 1:00 pm | No. 1 Loyola–Chicago vs. No. 3 Illinois State | 65–49 | CBS | |
| |||||
* denotes overtime period