The stars became husband and wife during a ceremony at the Marigny Opera House on Saturday, April 20, seven months after welcoming their first child together, son Rhys.
The tot and his big sister Owen, Michelle's 13-year-old daughter from her first marriage to bassist Teddy Landau, were both in attendance at the nuptials, along with other relatives and close friends, reports People.com.
Michelle had been counting down to their big day on Instagram, sharing a photo of a bottle of beer in a customised koozie from the city's Domilise's Po-Boy & Bar on Thursday.
"we here (sic)," the "Breathe" singer captioned the snap, announcing their arrival in New Orleans.
She followed it up with a picture of the happy couple kissing at a boozy party on Friday night, writing, "Love is in the air (and tequila after champagne was a bad idea)."
Patrick also documented part of the wedding preparations on social media, uploading an image of little Rhys sitting on his lap, while the baby was having his hair trimmed.
And hours after tying the knot, Michelle returned to Instagram to update fans about her relationship status by sharing a screen shot of a news alert on her cell phone, with the People.com headline reading, "Michelle Branch marries the Black Keys' Patrick Carney in New Orleans."
"Can confirm," she noted.
She and Patrick began dating in 2015, after meeting at a Grammy Awards party in Los Angeles and becoming collaborators on Michelle's most recent album, "Hopeless Romantic".
She moved into Patrick's Tennessee home in 2016, and the drummer proposed in July 2017, on Michelle's 34th birthday.