The actress, who plays Nell Fairfax in the ITV soap, said she was left crying after being "sexually harassed" while on the Tube this weekend.
Hitting out at the alleged attacker in a furious Twitter post, she wrote: "To the guy who just sexually harassed me on the tube - I hate you.
"I hate you SO much but I didn't have the guts to say anything. I just took it. Then cried. Like too many women. I'm glad we're getting angry."
She continued: "Btw, I know this isn't a gender thing and plenty of men have to go through this too.
"It's just heartbreaking because all down to respecting your fellow humans. All my love is with you guys. I love you so much."
Her comments were met by a flood of support from followers, with one replying: "Hope you're ok Scarlett such an awful thing to happen and so upsetting."
Another wrote: "That's disgusting Scarlett hope you're OK ... don't let the scum drag you down ... Hopefully karma will do its thing."
One fan urged: "Hope that you are okay ... please please report this to the Police. He cannot be allowed to get away with it or be in a position to do this to another female."
Archer's comments come amid a wave of complaints made by actors and actresses about inappropriate sexual behaviour following a number of allegations against movie mogul Harvey Weinstein.