She also said that lewd comments Donald Trump made about women that were caught on videotape were unacceptable but did not represent the man she knows.
The Republican presidential nominee was guilty of "boy talk" but was "egged on" by TV host Billy Bush, she added.
The tape prompted dozens of Republicans to drop their support for him.
In the video, Mr Trump tells Mr Bush, who was then host of NBC's Access Hollywood, that he can force himself on women because he's a star.
Several women have since come forward and accused Mr Trump of sexual assault, which he denies.
"I know he respects women but he is defending himself because they are lies," Mrs Trump said in an interview with CNN.
"I believe my husband," she said. "My husband is kind and he is a gentleman and he would never do that."
She claimed the scandal had been "organised and put together to hurt his candidacy" by Hillary Clinton's campaign team and the media.
"With the details [the media] have got, did they ever check the backgrounds of these women? They didn't have any facts," she added.
Speaking for the first since the scandal began, Mrs Trump defended her husband's conduct with women, saying he had never behaved inappropriately over the years.
Women commonly approached her husband in front of her to give him their phone numbers and behave inappropriately, she said.
Reflecting on the 2005 Access Hollywood videotape leaked to the media 10 days ago, she said: "I said to my husband that, you know, the language was inappropriate. It's not acceptable.
"And I was surprised, because that is not the man that I know."
After the taped remarks became public, Mrs Trump issued a statement saying she found the words he spoke to be offensive but she accepted his apology.
Now she believes Billy Bush, who was fired by NBC over the tape, was the main culprit.
Mr Trump, she said, "was led on - like, egged on - from the host to say dirty and bad stuff".
She also justified her husband's tactic of appearing with the women who have accused former President Bill Clinton of sexual assault.
With three weeks to go before Americans cast their vote, polls show Mr Trump with considerable ground to make up on Democratic rival Hillary Clinton in key battleground states.
Who is ahead in the polls?
48%
Hillary Clinton
44%
Donald Trump
Last updated November 8, 2016
Melania Trump has insisted that her husband is a "gentleman" and that the women who allege that he sexually assaulted them are lying.