Charlie Puth's family just got bigger ... Monday, the singer announced the arrival of his first child, Jude, in an Instagram post cheekily referencing the Beatles' hit "Hey Jude."

He shared a carousel of sweet shots of the baby ... including hospital polaroids with his wife Brooke.

She also shared an adorable image of their newborn on her Instagram story ... writing "my whole world."

According to Charlie's IG, Jude was born on March 13.

He first revealed he and his wife were expecting back in October, dropping the news in a clip from his "Changes" music video.

They've been documenting the journey on social media, sharing photos of baby bumps and sonograms.

Congrats to the new parents!