Upton will be taking on the additional responsibilities alongside her existing role of CIPD membership and marketing director, responsible for continuously improving the benefits, services and value current and future CIPD members derive from the Institute.
This is a new role, recognising the long-term absence of Jackie Orme, the CIPD's chief executive, who is undergoing treatment for cancer.
Gill Rider, CIPD president, said: "I have met with Jackie Orme in recent weeks, and she has made clear to me that she will be unable to return to work in the immediate term. With Jackie's blessing, the board has therefore decided to appoint Sue Upton to direct the Institute in Jackie's absence.
"Sue will be supported by her executive team colleagues - all of whom also continue to take on additional responsibilities to ensure that Jackie's absence does not reduce our capacity to serve members, lead the profession and deliver against our objectives. I, and the rest of the board, also remain committed to providing whatever support is required.
"Members and customers should not be impacted. Our vision and objectives remain as clearly set out by Jackie, and our focus is on continuing to deliver these for the HR profession and the Institute."
Upton added: "All of our thoughts at the CIPD are with Jackie Orme and her family at this time. We've also been grateful for all the kind messages of support we've received for Jackie from HR professionals and others in the UK and around the world.
"My focus in taking on this interim role will be on working with all of my colleagues to ensure we deliver on the vision Jackie has set for the CIPD and the wider profession".