The former Destiny's Child singer joined the show last year, but will be replaced in this year's judging lineup.
"After much speculation, we can officially confirm today that Kelly Rowland has decided not to return as a judge again for this year's UK X Factor," her spokesperson said.
"Global commitments coupled with the show's increasing demands this year mean that, despite weeks of deliberation with the show, Kelly has not been able to agree a deal that fits into her autumn/winter schedule, so sadly cannot accept a place on the 2012 panel.
"Kelly thoroughly enjoyed her role as a judge on the show, but felt that if there couldn't be a workable solution to scheduling issues so that she could effectively juggle her other commitments then she couldn't wholeheartedly commit to the show this year."
Rowland said: "I love the UK and being part of the show last year. Mentoring the girls was such an incredible experience I will never forget. I would like to thank Simon for the great opportunity and asking me to be a judge last season."
A spokesperson for The X Factor said: "Kelly's immense experience in the music industry shone through in both her judging and mentoring on The X Factor and we would like to thank her for being a part of the country's number one show and wish her well for the future."
They added: "The judging panel will be announced in due course."
Show host Dermot O'Leary recently told Digital Spy that he would like to see Rowland back on the panel, adding that the programme needs "continuity".
Dannii Minogue, who was on the judging panel between 2007 and 2010, has been tipped to return in place of Rowland. It recently emerged that Minogue had a fling with show boss Simon Cowell in 2007.
Fellow judge Tulisa Contostavlos has said that she would get on with Minogue should she return to the show.
Gary Barlow confirmed his return to the head of the panel earlier this month and is said to have signed a £2 million contract.