A date for the move has yet to be confirmed, said a spokeswoman from the Portsmouth trust.
Ms Rix, who has 15 years experience of director-level nursing positions in both acute and integrated trusts, has been at University Hospitals of North Midlands since 2009.
“Portsmouth has recently made some significant positive strides”
While there, she oversaw the organisation being rated “outstanding” for caring by the Care Quality Commission.
Ms Rix moved into management after completing the NHS Management Training Scheme where her experience included working with the Welsh Assembly government on developing performance monitoring.
Following her appointment, Liz said: “I am extremely proud to become the newest member of the PHT board in my role as chief nurse.
“I believe that the key to good outcomes for staff and patients comes from having the right staff with the right skills to deliver within a framework that supports pride and respect,” she said.
“Being a nurse on the trust board offers a privileged opportunity to influence the delivery and design of services,” said Ms Rix, who is also a member of the Nursing Times advisory board.
She added: “Portsmouth has recently made some significant positive strides and I aim to continue this trend while supporting the nursing workforce in any way I can.”
Mark Cubbon, chief executive of Portsmouth, said: “I am delighted to welcome Liz to the trust and to join me and colleagues as part of the leadership team.
“Liz brings a wealth of experience and a strong track record of clinical leadership supporting the delivery of safe and compassionate care to patients,” she said.
“I have no doubt that she will make a positive contribution to us all at PHT and importantly, to the patients and communities we serve,” she added.