Prison officer Bailey was crowned the UK's 10th X Factor winner after the public picked her over 17-year-old Nicholas in the final show of the series.
The Motherwell teenager was beaten in the final stage of the competition after performing Superman by Five For Fighting.
Bailey, a 36-year-old mother of two, has won a recording contract and will support American pop superstar Beyonce on the UK leg of her Mrs Carter world tour in February.
The clear favourite before the announcement, she was speechless after being told she had received more than a million votes after her performance of Skyscraper by Demi Lovato.
Nicholas, a pupil at St Aiden's High School in Wishaw, accepted his defeat gracefully and said he would still make it in the music industry.
He said: "If I was getting beaten by anybody, it was going to be Sam.
"I just want to say thank you to absolutely every single person who voted for me. This is not the end of me - I know I'll have an album out."
The pair went head to head in front of 10,000 fans at last night's live final at Wembley Arena.
Speaking before the winner was announced Nicholas's mother, Eileen McDonald, said: "Nicholas has already won, just to get this far.
"He has grown in confidence week by week although the public have not quite seen his real personality come through. We call him Tricky Nicky but that cheekiness has not come through.
"We are incredibly proud of him, though."
Bailey was quick to sing her competitor's praises.
She said. "He's got the most amazing voice. I love him to death."