Walter Jacob Hollenweger (born 1927) is a Swiss theologian and author, recognized as an expert on worldwide Pentecostalism. His two best known books are: The Pentecostals (1972) and Pentecostalism: Origins and Developments Worldwide (1997) 
In 1955 he began studying at the Faculty of Theology of the University of Zurich. He wrote a ten volume doctoral dissertation Handbuch der Pfingstbewegung (Handbook of the Pentecostal Movement) published in 1966. The core of this work was published in various languages and became a standard work on Pentecostalism. His numerous publications in the years following made him one of the premier interpreters of this movement.
Hollenweger, who served as the first Secretary for Evangelism in the Division of World Mission and Evangelism of the World Council of Churches from 1965 to 1971, continues to be a staunch advocate of ecumenism for Pentecostal churches. 
Named in his honour, the Hollenweger Center  at VU University, Amsterdam, is an academic platform for and across different disciplines within the field of Pentecostal/Charismatic studies, providing opportunities to study Pentecostalism on MA and PhD level (theology, missiology, religious studies, anthropology of religion).
- * Hollenweger, W.J., The Pentecostals (Minneapolis: Augsburg Publishing House, 1972)
- Hollenweger, W. J., Pentecostalism: Origins and Developments Worldwide, (Hendrickson Publications, 1997).
- European Pentecostal / Charismatic Research Association, Press Release, July 17, 1999 Retrieved Oct 6, 2007.
- European Research Network on Global Pentecostalism, ‘’ Bibliography Walter J. Hollenweger’’, 2005 Retrieved Oct 6, 2007.
- The Ecumenical Quest for Pentecostalism, Cyberjournal for Pentecostal-Charismatic Research Retrieved 23 Sep 2007.
- Postgraduate Programmes in the Centre for Pentecostal and Charismatic Studies at the University of Birmingham, Graduate Institute for Theology and Religion, University of Birmingham Retrieved 23 Sep 2007.
- Hollenweger Centre
- Christianity Today, The Rise of Pentecostalism: An Interview with Walter J Hollenweger, Jan 1998 Retrieved Jan 11, 2009.