The comic is currently appearing in the final season of NBC sitcom 30 Rock, in which he stars alongside Tina Fey and Alec Baldwin.
Now, Morgan's fiancée Megan Wollover is pregnant with the couple's first child together, reports US Weekly.
Morgan already has three grown sons with his ex-wife Sabrina. The couple divorced in 2009 after 23 years of marriage.
The 44-year-old announced his engagement to Wollover in September 2011, after proposing six months earlier.
In a recent interview with Rolling Stone, the comic expressed his desire to have a daughter one day, adding: "You know what happiness is? Happiness is a simple thing, man. It's having something to look forward to."
30 Rock co-star Alec Baldwin is also rumoured to be expecting his first child with wife Hilaria Thomas.
30 Rock airs its season finale tonight (January 31) at 8/7c on NBC.
Watch a clip from 30 Rock below: