Fatima Payman, who is Muslim and does not drink alcohol, was at a social event as part of parliamentary business when she says an older, male colleague made comments like "let's get some wine into you and see you dance on the table".
"I don't drink and I don't need to be made ... to feel left out because you do," she told ABC's Triple J radio station.
"I told this colleague, 'Hey, I'm drawing a line, mate', and moved on to making a formal complaint."
The former Labor senator quit the party over its stance on Palestine and sits in the upper house as an independent.
She said poor conduct shouldn't be brushed under the rug.
"If that something makes you feel uncomfortable, call it out and say 'yeah that wasn't cool'," Senator Payman said.
The issue has been escalated to the Parliamentary Workplace Support Service, a body established after staffer Brittany Higgins made public allegations about being raped in Parliament House by a colleague.
Senator Payman said the support service had taken care of her and she was happy with the swift handling of her complaint.
Independent senator Lidia Thorpe's complaint with the agency relating to sexual harassment allegations against Victorian senator David Van remains unresolved.
Senator Van denies the allegations and became an independent after quitting the Liberal Party in 2023.
His term will finish at the end of June as he wasn't re-elected at the May federal election.
Opposition Leader Sussan Ley said she read reports about Senator Payman's claims with "great concern".
"It is simply not good enough to have that behaviour take place in this building," she told reporters in Canberra.
"It is vital that reporting of events like this are a reminder to everybody that we must never take our eye off the ball when it comes to continuous improvement in the culture in this building."
The service managed 339 cases between 2023 and 2024, according to its most recent annual report.
Just under one in 10 cases related to rape and sexual assault, harassment, assault, sexual harassment, stalking or intimidation.
A similar proportion were about bullying, about one in five related to family and domestic violence, alcohol and drugs or mental health, while roughly one in four were over workplace conflict.
The vast majority were related to staff who help politicians carry out duties, but not for party political purposes, though 17 involved parliamentarians.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
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