Most remembered for his emotional performances in the late 1930s films Boys Town and On Borrowed Time, Watson is also notable for his appearances in episodes of The Beverly Hillbillies, The Virginian, and Lou Grant.
He appeared, uncredited, in several Hollywood features before playing a billed role as a little boy in the 1937 movie She's Dangerous.
He received his Methodist ordination from the Claremont School of Theology and worked as a minister for three decades.
The sibling of fellow child actors Coy Watson, Jr., Billy, Harry, Garry, Delmar, Gloria, and Vivian Watson, Robert "Bobs" Watson grew up in Los Angeles, California. His marriage to Jaye Watson produced three children.
Watson developed a lifelong friendship with his Boys Town co-star Spencer Tracy.