Turner and fellow former Blue Peter presenter Diane-Louise Jordan attended the trial at Southwark Crown Court to support Leslie, 55, who was cleared of sexual assaulting a woman at a Christmas party in London in 2008.
Turner, 60, shared a picture of the trio on Instagram, writing: “John Leslie has AGAIN been given the verdict NOT GUILTY The shot was taken last week after Diane and I joined him and his Dad at Southwark Court.
“Unbelievable relief for our amazing gentle giant of a friend but personal anger that he has had his life ripped apart over the years, however justice has today prevailed and I couldn’t be happier.”
Leslie, full name John Leslie Stott, cried and nodded at the jury as the verdict was delivered, and made no comment when he left court.
Watch: John Leslie leave court after being found not guilty of sexual assault
He had denied the accusations that he had groped a woman after shaking hands with her in London’s Soho over 10 years ago.
It took the jury just 23 minutes to return the a verdict of not guilty, after the week-long trial.
Leslie had elected to be tried by a jury, rather than at magistrates’ court, despite the offence being deemed appropriate to be decided by a district judge.
He told the jury that he could not remember being at the party in question and said the single allegation of sexual assault was "crazy" and "ludicrous".
"I would not have touched her like some mannequin and walked off," he said during evidence, adding that he had been made out to be an "aggressive, sexual monster" by the tabloid press and denied ever assaulting any woman.
Leslie also told the trial that his life changed completely in 2002 when he was wrongly identified on live television as the unnamed alleged rapist in a book by his former girlfriend, Ulrika Jonsson.
Presenter Matthew Wright later apologised, saying he named Leslie in error.
In 2003, two charges of indecent assault, made against Leslie, were dropped and not guilty verdicts recorded.
Leslie was also arrested and interviewed by police in 2008 over an allegation of rape and indecent assault that was said to have happened in 1995, the jury was told.
However, there had been insufficient evidence to charge him and no further action was taken.
Leslie joined BBC children’s magazine show Blue Peter in 1989 and remained with the show until 1994, working with both Turner and Jordan, 60.
In 1998 he took over from Bradley Walsh as the main presenter of game show Wheel Of Fortune, before joining This Morning a year later. He was replaced on the morning show by Phillip Schofield in 2002.
Between 2012 and 2016, Leslie had short stints as a radio DJ in Scotland with Castle FM and Bauer Radio.