No, since computer fans are DC. You can get AC fans that you can wire straight to the same power cord as your ballast, so they come on when the ballast comes on. The Orion fans are popular among the AC fans.
With the DC fans, you have to wire them to an adapter. Any old cellphone charger, etc. will work. Just check the voltage and amperage of the adapter and fans to make sure they match. For example, my computer fans are 12v and 100 mA. I found an old AC adapter that was 12v and put out 300 mA, so it would be able to run 3 of the fans.