Luo Union was founded as a Luo welfare association in the 1920s in Nairobi after several Luo welfare associations folded up to form one umbrella union. Its aim was to unite Luos in Kenya and later spread to East Africa by building a cultural unity around Luo identity.
It catered for social support causes among Luos in urban centres until graduates from Maseno School and Alliance High School led by Jaramogi Oginga Odinga showed up in the 1940s. By 1950, the union had about 3,000 members with branches in Dar-es-Salaam, Mwanza, Kampala, Kisumu and Nairobi.