The two celebrities came forward to reveal the alleged abuse after the disgraced Australian star, 84, was jailed for nearly six years for a string of sex attacks on girls as young as seven.
Feltz, 52, claims Harris inched up her leg and put his hand inside the elastic of her knickers in front of millions of viewers while she was interviewing him live on The Big Breakfast.
She claimed Harris attacked her while filming the On The Bed section of the show in May 1996.
Feltz said she noticed "a rustling" at the hem of her dress and felt Harris's hand creeping up her leg.
The TV presenter said she wanted to put her hand out to stop Harris, but she was live on TV and was terrified of doing something that would upset the millions of children watching the show.
She said: "After a few seconds he had managed to get his hand inside the elastic of my knickers and I was absolutely staggered."
She told police about the alleged assault, but the judge at Harris' criminal trial ruled the evidence could not be admitted.
Meanwhile, Nolan claimed she was just 15 and on tour when Harris groped her in a corridor. The star, 55, said she was on her way to get ready for a performance when Haris pounced on her backstage at the concert in South Africa in 1975.
She said: "He suddenly came out of nowhere. His arms were all over my back, right around me so his hands were touching the sides of my breasts.
"He rubbed up and down and started kissing and licking the back of my neck."
Both women waived their legal right to anonymity to reveal the alleged abuse.
A Scotland Yard spokesman said police did not comment on the identity of alleged victims of sex assaults.