The fund manager said Fleming will be responsible for its global distribution platform that employs 450 people across business development, product specialists, marketing and client service.
He is currently global chief operating officer and chief executive for Europe, the Middle East and Africa at rival Columbia Threadneedle, having previously served as head of distribution at JP Morgan.
Columbia Threadneedle chief executive Ted Truscott said: “Campbell made many contributions during his six years with the organisation, including expanding our distribution capability and further strengthening our position in the marketplace.
“We have a strong and experienced leadership team in place and we remain focused on delivering successful investment outcomes and solutions for our clients.”
In his new role, Fleming succeeds John Brett, who stepped down as Aberdeen’s global distribution chief at the end of last year.
Aberdeen chief executive Martin Gilbert said: “We are delighted to attract someone of Campbell’s calibre – this reflects the appeal of our global platform and our full-service capability across asset classes and strategies.
“After an in-depth worldwide search process, Campbell was identified as the outstanding candidate given his expertise and experience across client channels globally, including North America which is a key focus for us.”
In January, Aberdeen said it expected market conditions to remain “difficult” as it announced the retirement of chairman Roger Cornick.
The fund manager also said it had identified further cost savings on top of a previous target of £50 million. More details will be given alongside its half-year results, due next month.