Born in August 1963, Justice Daniel Kiio Musinga graduated from the University of Nairobi with a Bachelor of Laws (LLB) degree in 1987. Upon completion of a Diploma course in legal practice at the Kenya School of Law (KSL), he was admitted to the Roll of Advocates in 1988.
During his private legal practice, he served as a legal assistant in the firm of Gikandi & Company advocates in Mombasa from 1988 to 1991. He founded his law firm, Musinga & Company Advocates in October 1991 and remained in active legal practice until 2003, when he was appointed Judge of the High Court of Kenya.
Prior to his appointment as a Judge, Justice Musinga had been appointed by President Mwai Kibaki as a member of the Tribunal to investigate the conduct of Judges who had been suspended in 2003. He also chaired the Mombasa Law Society of Kenya as well as the Kenya Christian Lawyers fellowship, an organization established as a legal aid programme, Christian Legal Aid & Research (CLEAR) for purposes of rendering pro-bono legal services to deserving persons, between 2001 and 2003.
His first posting as a Judge of the High Court of Kenya was in Nakuru, where he served until 2008 when he was transferred to Kisii. At Kisii, he was nominated by the Law Society of Kenya for the award of outstanding Judge in administration of Justice for the year 2010. In 2011, he was honoured by the International Commission of Jurists (ICJ), Kenya Chapter, as the Jurist of the year; he was then serving in the Constitutional and Judicial Review Division, Nairobi. In 2011, he was appointed Presiding Judge, Commercial and Admiralty Division, Nairobi.
Justice Musinga was appointed Judge of the Court of Appeal in December 2012 and in May 2021, he was elected the president of the court.