Murray, who was deputy mayor for housing for more than three years, won the seat after securing a 12,269 vote majority over his Conservative rival Anthony Pickles.
He succeeds the former Labour MP and shadow minister for Northern Ireland Stephen Pound, who announced in July that he would not be seeking reelection.
Murray’s Twitter bio now states: "Labour and Co-operative MP for Ealing North. Former Deputy Mayor of London for Housing."
The Greater London Authority confirmed Murray is no longer deputy mayor for housing and advised that deputy mayor for planning Jules Pipe is fulfilling the role on an interim basis.
"A replacement for James will be announced in due course," a spokesman said.
Prior to joining Khan’s mayoral team in May 2016, Murray served as a councillor in the London Borough of Islington, where he helped spearhead efforts to improve transparency over viability assessments.
During his tenure, Murray oversaw the publication of the draft New London Plan in November 2017, which included new policies aiming to boost housing densities and encourage more homes on small sites, and new planning guidance on affordable housing and viability.
Also celebrating an election win after last week’s ballot was chartered town planner Helen Hayes, who was re-elected as Labour MP for Dulwich and West Norwood in south London, beating rivals including Green Party co-leader Jonathan Bartley.