Schumer posted on Instagram Monday afternoon that the child, a boy, was born 10:55 p.m. Sunday.
"Our royal baby was born," she wrote, a nod to Prince Harry and Meghan Markle's newborn son who arrived just hours later.
Schumer did not disclose the baby's name. She had previously announced the child's sex in a separate Instagram post.
SEE MORE: Celebrity moms who've welcomed new babies this year