The lawsuit was filed in Los Angeles County Superior Court by civil-rights attorney Lisa Bloom on behalf of a client identified only as Jane Doe, who was 16 at the time.
Lawyer Patricia Glaser said in a statement Thursday that Cardenas is "sickened and distraught by these horrific allegations, which are 100%, categorically untrue."
Bloom had not identified which L.A. elected official was being accused when the lawsuit was announced on Friday.
Lawsuit accuses unnamed LA elected official of sexually abusing teen in 2007
"Once the court grants that permission," she added, "we will amend the complaint to include the defendant's name, as California law permits."
The lawsuit alleges that the defendant invited the then-teenager to play golf with him at Hillcrest Country Club and sometime during the round gave her a cup of water that had a "peculiar taste."
The girl later collapsed but was still conscious. According to the suit, while driving her to a hospital, the man intermittently reached inside her shirt and down her pants, touching her breasts and vagina.
She pretended to be asleep out of fear of what he might do. The lawsuit also described a later incident at the teen's father's place of business, in which the politician told her: "Remember where your dad works."
The plaintiff perceived that statement as a threat against her family's security.
Glaser said the complainant is the daughter of a "disgruntled former employee and may be the victim of manipulation," adding that the claims are false and "utterly inconsistent with who he is - in the workplace, in the community, and at home."
The Washington Post reported that Cardenas has been calling fellow Democrats in Congress claiming his innocence.
Authorities from the LAPD said Thursday there is no criminal investigation into Cardenas at this time.
The alleged victim in the case is now grown, married with a daughter on the way. She said in the suit that she came forward now because of the #MeToo movement and for her daughter.