The research studied the effectiveness of the integration of Facebook as a flexible ubiquitous learning space into the educational process for speaking skills development of undergraduate students learning English as a second language. For this purpose teaching was organised via a specially created and moderated Facebook group where various media resources, uploaded materials, links to different applications and other social networking opportunities were accumulated. It was designed to achieve the educational programme objectives and address the specifics of digital age learning. A set of specially designed materials posted on the Facebook platform for language input, structured output, and communicative output activities was applied in experimental teaching to develop talk as transition, talk as interaction and mediation, and talk as performance. The results of the quasi-experiment (students' speaking performance) were assessed in the form of the post-test with the data being analysed and interpreted based on descriptive and inferential statistics (independent samples t-test) by means of SPSS. The results revealed higher achievement scores of the experimental group in comparison to the control group in terms of expanding vocabulary, increasing English grammar literacy, developing interactive skills, discourse management, and pronunciation. The survey administered to find out the learners' impressions of the successfulness of the FB-assisted activities revealed their overall positive attitude to the new methodology and usefulness for the development of all speaking qualifications checked.