A family member can include former or current partners and extended family members including offspring or siblings.
The commission says the leave option will help workers who are facing family and domestic violence, and find it "impractical to do so outside their ordinary hours of work".
However, it doesn't apply to workers who are covered by specific industry awards or those who have no formal agreement.
However, some of these workers might be able to get other paid or unpaid entitlements in their awards. Some employers also allow workers to take family and domestic violence leave.
Experts are advising employers and their staff to have open and reassuring discussions about the new leave offering coming into place.
Workplace specialist firm Employsure's Senior Employment Adviser, Nicholas Hackenberg, told News Corp Australia that employers must remind their employees they will consider all the information they receive as confidential, and cannot assume men are exempt from domestic violence either.
Hackenberg said employers should also take requests for domestic violence leave should be taken seriously by employers, even if they don't believe their workers are telling the truth.
"In the #metoo era with an increased public awareness of sexual harassment and domestic violence, employers need to recognise that allegations of domestic violence, inappropriate workplace behaviour, sexual harassment in and outside the workplace should be taken very seriously," he said.
"If requests for support are not adequately responded to, they may instead be played out in the media or through litigation against the employer for its lack of support. Rather than refusing the request it is sometimes, in the employer's best interest to allow the employee the time off that they need in order to seek the support they need."
For those workers who need further help, he said they "can seek external support to ensure they receive their rights".
While he acknowledged that there are laws already in Australia that require employers to manage workers facing domestic violence, he described this new leave entitlement as "an additional safety net to protect victims".