The 47-year-old "Can You Stand the Rain" hitmaker announced the news of his newest arrival on Instagram.
Brown posted a picture of himself with the caption- "Just had a baby girl 10 pounds."
Brown and Etheredge are already parents to 12-month-old daughter Bodhi Jameson Rein and son Cassius who is seven.
The singer had posted his expecting wife's photo three days back on his Instagram, writing, "Love is @aliciaebrown MY QUEEN MY ROCK MY EVERYTHING."
Brown also has three children from previous relationships- Landon, La'Princia and Bobby Jr. His daughter with the late singer Whitney Houston, Bobbi Kristina Brown, died at the age of 22 in July 2015.