'''Felix Yanwar Siauw, [[Sarjana Pertanian|S.P]]''' ({{zh|first=t|t={{linktext|蕭|正|國}}|s={{linktext|萧|正|国}}|p=Xiāo Zhèng Guó}}, {{lahirmati|[[Palembang]], [[Sumatra Selatan]]|31|01|1984}}) adalah seorang [[ustaz]], pendakwah, dan penulis beretnis [[Tionghoa-Indonesia]]. Ia menjadi seorang [[mualaf]] semenjak masa kuliah dan bergabung menjadi salah satu aktivis gerakan Islam, [[Hizbut Tahrir]] Indonesia (HTI).<ref name=masuk>Masuk-Islam. 28 Maret 2013. [http://www.masuk-islam.com/kisah-felix-siauw-masuk-islam.html Kisah Felix Siauw Masuk Islam].</ref> Ia dikenal karena afiliasinya dengan kelompok Islamis HTI dan posisi puritan garis kerasnya dalam penafsiran Islam.<ref name="Au">[http://www.theaustralian.com.au/news/from-indonesian-village-to-philippines-siege-chief/news-story/9b34addb7f4ce5a7b08f1a1ba50b9b9f From Indonesian village to ISIS siege chief.] ''The Australian''. Retrieved October 18, 2017.</ref><ref name="ST">[http://www.straitstimes.com/asia/se-asia/indonesian-government-acts-to-ban-radical-group Indonesian government acts to ban radical group]. ''The Straits Times''. Retrieved October 18, 2017.</ref>
Populer di media sosial, ia dikenal karena sikapnya yang suka mengkritik [[demokrasi]], [[nasionalisme]], [[kapitalisme]], [[sosialisme]], [[feminisme]] dan [[sekularisme]].<ref>{{Cite book |last=Wai Weng |first=Hew |title=Mediatized Religion in Asia: Studies on Digital Media and Religion |publisher=[[Routledge]] |year=2019 |editor-last=Radde-Antweiler |editor-first=Kerstin |pages=94 |chapter=On-Offline Dakwah: Social Media and Islamic Preaching in Malaysia and Indonesia |editor-last2=Zeiler |editor-first2=Xenia}}</ref>