He is the author of the book Wired Shut: Copyright and the Shape of Digital Culture.

He obtained his Ph.D. in Communication from the University of California, San Diego in January 2002.

[citation needed] Gillespie is currently researching the impact of the Internet and modern media technologies on copyright law and the progression of copyright law in the digital age.

Broader interests include debates on peer-to-peer file-sharing, information technology, animation and children's media.

His 2018 book Custodians of the Internet discusses the complex relationship social media sites have with hate speech and extremist groups on their sites, as there are no defined "custodian" responsibilities in policing this content, and actions taken are mainly left up to the discretion of private companies.