The 33-year-old singer announced the happy news on Thursday on her Twitter account.
“Our little baby boy has arrived!! Remington Alexander Blackstock was born 4/12/16 & he is healthy & we couldn’t be happier or more in love!” Clarkson tweeted.
The Miss Independent singer revealed her second pregnancy in August during a concert at Staples Center.
“I was not planning on announcing this, but … I’m totally pregnant,” Clarkson said while singing “Piece by Piece.”
The former American Idol winner and her husband, who tied the knot in 2013, are already parents to daughter River Rose, nearly 2. Blackstock also has two children from his previous marriage to Melissa Ashworth White, son Seth and daughter Savannah.