Sylvanus Onyiego Osoro (born 1988) is a Kenyan politician, advocate of the High Court and Certified Public Accountant who serves as the Majority Chief Whip in the 13th Parliament and Member of Parliament for South Mugirango Constituency in Kisii County. First elected to the National Assembly in 2017 on a KNC ticket and re-elected in 2022 under the United Democratic Alliance (UDA), he occupies one of the most strategic leadership positions in the Kenya Kwanza government’s parliamentary line-up, responsible for marshalling government business and enforcing party discipline on the floor of the House. His journey is frequently described as “grass to grace”: after a difficult childhood that included a stint as a street boy in Nairobi following the death of his parents, he worked his way through school from Chemasingi Primary and Hill Secondary School, qualified as a CPA, ventured into business and local gospel ministry, and ultimately transitioned into national politics as a second-term MP. Osoro’s professional and academic profile underpins his reputation as both a technocrat and a combative political operator. He completed CPA training before earning a Bachelor of Laws (LLB) from Mount Kenya University, a Postgraduate Diploma in Law from the Kenya School of Law and later embarking on a Master of Laws (LLM) at the University of Nairobi, while also being admitted as an advocate of the High Court of Kenya. In Parliament he has served on key committees such as Defence and Foreign Relations and the Committee on Implementation, and as Majority Chief Whip he has become one of the most visible defenders of the Kenya Kwanza administration’s agenda—regularly speaking out on contentious issues including taxation policy and the “shareholders” rhetoric in national politics, while also featuring prominently in high-stakes legal and political battles over the coalition’s majority status in the House.