Yes. You can buy a program or find a fee converter on the web. Search for "convert WAV files to MP3 files. Some you have to do one at a time and can be very time consuming if you have a lot of music. But you must convert them to put them into Itunes.
There are a lot of free applications on the web to do this. One that works quite fine and allows you also to work on the file is Audacity. It comes for Windows and Linux and allows to import and export different formats.
Well to do this you will need some program capable of converting audio files to other formats. Look online for a guide on which ones are better for this.