baby face

a face having a bland babyish or childish appearance, especially a plump, small-featured face unmarked by characteristic lines.

a person having such a face.

Origin of baby face

First recorded in 1705–15

ba·by-faced, adjective

Paul Ryan, WI-6 (R), is the baby-face of the lot, no money, but lots of braininess about taxes and spending.

The GOP's Oompa-Loompa |John Batchelor |September 2, 2010 |DAILY BEAST
Tell me, O chiefs,” said the great khan, “is that baby-face you look at worth contending for?

The Pacha of Many Tales |Frederick Marryat
The old man's thoughts travelled back to the time when he first looked upon the baby-face of the cold hard grey form before him.

London's Heart |B. L. (Benjamin Leopold) Farjeon
The same sweet smile lingered about his mouth, although pain and suffering had saddened that baby-face.

The Nest in the Honeysuckles, and other Stories |Various

At the door, he hesitated; and, drawing forth the little picture, looked again at the baby-face.

The Rector of St. Mark's |Mary J. Holmes
Can it be possible you are on the other side—on Baby-face's side?

The Harmsworth Magazine, Vol. 1, 1898-1899, No. 6 |Various

baby-face

a smooth round face like a baby's

a person with such a face