This paper tends to ascertain the application and use of social networking tools among librarians in Nigerian libraries and its effect in the delivery of library services. The population of study was librarians in Nigeria. A structured online questionnaire was posted on Nigeria Library Association (NLA) online forum. A total of 75 librarians from different libraries across Nigeria responded to the questionnaire. The researchers randomly selected 10 respondents each from the six geopolitical zones in Nigeria. A total of 60 respondents were therefore selected representing the zones which were used for the study. Findings reveal that few academic libraries (22%) in Nigeria have dedicated social networking sites on the Internet. It however shows that librarians in Nigeria used social networking tools such as Facebook, Google+, LinkdIn, YouTube, Blog and Twitter among others to receive and share information and research outcome with colleagues. The study further reveal that social media was grossly underutilized for core library services. The researchers therefore recommend that Libraries in Nigeria should endeavour to create corporate social networking sites and encourage librarians to use social media for core library activities to enhance delivery of prompt and adequate services to library clientele.