An alternative to virtualization (which is already covered in other answer) would be to use a Windows runtime environment emulation such as Wine.
PlayOnMac, the Mac version of PlayOnLinux, is a graphical frontend for Wine and provides configuration templates to run the windows version of Internet Explorer.
Although this solution has a lot of benefits (no virtual machine, no Windows license needed, no cost), it may be really tricky to set up if it doesn't work out-of-the-box. In which case a windows virtual machine would be the easier way to go.