Yes it has. By Mariah Carey. Her first 10 singles hit #1. She's had a total of 14 #1s. However, Billboard didn't have this chart until the mid 90s, taking away 10 of her #1s from their list. So, Bilboard counts Mariah with 4, but Mediabase counts her with 14.
Vision of Love, Love Takes Time, Someday, I Don't Wanna Cry, Emotions, Can't Let It Go, Make It Happen, I'll Be There, Dreamlover, Hero, Fantasy, One Sweet Day, We Belong Together, and Shake It Off have all hit #1 on Mediabase.
Only Fantasy, One Sweet Day, We Belong Together, and Shake It Off have hit #1 on Billboard's Top 40 Mainstream chart, because like I said, Billboard's Top 40 Mainstream chart didn't start until mid 90s.