The 51-year-old star - who has Sunday, 10, and Faith, eight, with his 'Aquaman' actress wife - put an end to Jason Aldean's winning streak, after he had picked up the prestigious honour three times consecutively at the ceremony for the past three years, whilst Keith also beat Luke Bryan, Kenny Chesney and Chris Stapleton to the title.
The 'Parallel Line' hitmaker, who was joined by Nicole in the audience, used his acceptance speech at the glitzy bash at the MGM Grand Garden Arena in Las Vegas to gush about his wife and their girls and thank his adorning fans.
He said: ''Thank you so much. Baby Girl, I love you so much.
''My team, thank you every one of you. To the fans out there, you are amazing. You have no idea what you mean to me. No idea.
''Baby Girl, I love you and our girls, Sunday and Faith, who are at home watching right now.
''My whole team ... I love you guys ... Country radio, I love you so much. Thank you so much. God bless every one of you.''
Keith had been nominated for the award nine times before his victory last night.
Jason didn't go home empty handed, as he received the Dick Clark Artist of the Decade prize, the highest possible honour, with only six artists having picked up the award.
The 'Lights On' hitmaker - who was joined on stage by Kelly Clarkson for a rendition of their 2010 duet 'Don't You Wanna Stay' - admitted he is ''very fortunate'' as he thanked his loved ones and fans.
He said: ''I feel very fortunate to have this.
''My wife ( Brittany Kerr), I love you. My family, my mom and dad are here. More than anything, thank you country music fans, country music radio. You've changed my life.''
It was also a big night for duo Dan + Shay, who took home three prizes; Best Vocal Duo, Best Song and Best Single Record for 'Tequila'.
Whilst Kacey Musgraves was named Female Artist of the Year and also won Album of the Year for the acclaimed 'Golden Hour'.
Kacey also put an end to Miranda Lambert's Female Artist of the Year streak, which saw her win the accolade every year since 2010.
The 30-year-old star - who was nominated alongside Miranda, Ashley McBryde, Maren Morris and Carrie Underwood - gave a short, but empowering, speech about staying true to her musical ''style'', even if other people don't think it will ''work''.
She said: ''I have to say that this award goes out to any woman, any girl or anybody, really, that is maybe being told that her perspective or her style is too different to work. It'll work out.''
An abridged list of the 2019 ACM winners is as follow:
Entertainer of the Year:
Female Artist of the Year:
Male Artist of the Year:
Duo of the Year:
Dan + Shay
Group of the Year:
Album of the Year:
'Golden Hour' - Kacey Musgraves
Single of the Year:
'Tequila' - Dan + Shay
Song of the Year:
'Tequila' - Dan + Shay
Video of the Year:
'Drunk Girl' - Chris Janson
Songwriter of the Year:
Dick Clark Artist of the Decade:
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