In 1942, a native of Dallas, Texas, the late Dr. Chester A. Hemphill organized Harmony Missionary Baptist Church. It was located on the corner of 4132 S. San Pedro St., in Los Angeles, CA., just down the street from Wrigley Fields Baseball Stadium, home of the major league Brooklyn Dodgers and the Los Angeles Angels. Dr. Hemphill converted a 'wood framed house' into a sanctuary of 80 seats. Dr. Hemphill already in his senior years, his wife, two daughter and his son, served the community for 17 years, before he retired in 1959.

In Summer 1959, the membership elected a new Senior Pastor, a native of Taylor, Texas, Dr. Lloyd T. Johnson. For over five decades, the Lord gave the increase through Dr. Johnson's ministry. Twenty-one sons were called to the ministry, eight of which were called to pastor. In 1972, the original 'wood framed house converted church' was demolished and a new Sanctuary was built. The following eleven years, the increase continued and four additional parcels were acquired. As a result of the continuing church growth, the current Sanctuary was built in 1983. Dr. Lloyd T. Johnson retired in 2014. He received recognition both Statewide and National. Dr. Lloyd T. Johnson is celebrated for his record-breaking Pastorship of 55 years. 

In July 2014, a native of San Antonio, Texas, Dr. Harold T. Johnson Sr. made history as the Third Elected Senior Pastor of the Harmony Missionary Baptist Church Inc. With an unwavering commitment and a new vision for Harmony MBC, Dr. Harold T. Johnson Sr. launched a Series of Ministries both Statewide, National and International, starting with THE “SPREADING THE WORD GLOBAL BROADCAST. You may connect with this International Ministry on TUNE-IN-Internet and locally on KALI Radio Station 900 AM.  In 2014, Dr. Harold T. Johnson Sr. founded the Harmony Bible Institute (H.B.I) Theological Seminary. Harmony Bible Institute Theological Seminary is accredited through Transworld Accrediting Commission International. Assistant Pastor, Harold T. Johnson II, administrates as Director of Academic Affairs.