I'm using NPSP and Volunteers for salesforce. Is there a way to import volunteer data that would either create or link them to an existing campaign and also record hours worked under the correct volunteer job?

There’s nothing out of the box that knows how to import v4 SF records. That said, a flat file that contains all the necessary, Fields, including contact, email, volunteer job name, hours works, date started, date ended, number of volunteers, Volunteer status can be imported. Creating a volunteer hour will link it all to the right volunteer job and to the volunteer campaign to with it belongs.

I personally use a modern import like Apsona that allows me to specify matching to a contact by email and matching to a volunteer job by name. If you don’t use a modern tool like that, you might have to use salesforce IDs instead.