Provided is a vibration-insulating rubber composition and a crosslinked vibration-insulating rubber composition which successfully maintain basic physical properties and thermal resistance while being excellent in weather resistance and crack growth resistance, and a vibration-insulating rubber using the vibration-insulating rubber composition and the crosslinked vibration-insulating rubber composition. The vibration-insulating rubber composition of the present invention includes: a rubber component having a conjugated diene compound/non-conjugated olefin copolymer; sulfur by 0.6 parts by mass or less per 100 parts by mass of the rubber component; and a bismaleimide compound by 1 to 5 parts by mass per 100 parts by mass of the rubber component.
