Roundup, round up or round-up might refer to:
- Ceiling function, the mathematical operation of rounding a number up to the next higher integer.
- Roundup, a term in American English referring to the process of gathering animals into an area, known as a "Muster" in Australia.
- Rounding up, when a helmsman can't control a boat and it heads into the wind
Music and entertainment
- "Round Up", a rap single by Lady May and Blu Cantrell
- Round-Up (video game), an arcade video game
- Roundup (album), an album by Denise Ho
- The Round-Up (1920 film), a 1920 Western film
- The Round-Up (1965 film), a Hungarian film by Miklós Jancsó
- The Roundup, a programme on CBC Radio One.
- Roundup, brand-name of an herbicide made by Monsanto, see glyphosate
- Roundup (issue tracker), web-based issue or bug tracking system
- Edsel Roundup, a 1950s estate car built by Ford
- The Round Up, a student-run newspaper publication of New Mexico State University
- Roundup, Montana, a city in the state of Montana
- Round Up (ride), an amusement park ride
- Operation Roundup (1942), the plan for an invasion of northern France by Allied forces throughout World War II
- Operation Roundup (1951), the attack launched by United States forces throughout the Korean War
- Roundup (history), in Polish łapanka, the practise in which civilians in Nazi-occupied cities were rounded up throughout World War II, mostly in occupied Poland