As part of the Linked Data For Production: Pathway to Implementation (LD4P2) project’s larger goal of building a pathway to the use of linked data in the description of library resources, we are exploring the integration of linked data sources in library discovery interfaces. Through a series of focused experiments and prototype building, aided by user studies and feedback, we have explored linking and displaying connections between library catalog data and linked data sources such as Wikidata and DbPedia as well as library authorities such as FAST, Library of Congress Subject Headings, and the Library of Congress Name Authority File. Examples of areas we investigated for the integration of linked data include: knowledge panels bringing in contextual information and relationships from knowledge graphs like Wikidata to describe people and subjects related to library resources in the catalog; suggested searches based on user-entered queries using results from Wikidata and DbPedia; and browsing experiences for subjects and authors bringing in relationships and data from Wikidata and library authorities. In this presentation, we will review the challenges and opportunities with bringing in information from external knowledge graphs into a library catalog to support discovery. LD4P2 (http://ld4p.org) is a multi-institution collaborative effort funded by the Andrew W. Mellon Foundation.