Acer may refer to:
- Acer (genus), the genus of trees and shrubs commonly known as Maple, from the Latin word ācer meaning sharp
- Acer Inc., a Taiwan-based international computer company
- the European Agency for the Cooperation of Energy Regulators (ACER)
- Armored Combat Engineer Robot (ACER), a military robot created by Mesa Robotics
- Australian Council for Educational Research, a non-governmental educational research organisation based in Camberwell, Victoria
- David Acer, stand-up comedian and Canadian close-up magician
- ACEr is used to identify a member of the American Coaster Enthusiasts