Phillips will join UBM's executive committee and report to CEO Tim Cobbold. She will be responsible for leading the company's HR function worldwide.
She replaces Sally Shankland, who moved from the HRD role to become CEO of UBM Americas in September 2014.
Before joining UBM, Phillips worked as SVP, HR for EMEA at technology company SAP. Earlier in her career, she held both regional and global HR roles at technology firms including Geac Computer Corporation and Lawson Software.
Cobbold said UBM brought Phillips on board to support its growth plans and refreshed corporate strategy.
"Eleanor brings with her a proven track record of leading HR teams in businesses recognised for their operational excellence, and businesses where both agility and local entrepreneurship were key to the company’s operating model," he said.