Advertising Week Europe, which was due to take place in London during 16-19 March, has been moved to 14-17 September.
The four-day event is one of the biggest fixtures in the UK advertising calendar, attracting more than 20,000 attendees.
"After careful consideration, Advertising Week Europe has made the difficult decision to postpone the event to 14 to 17 September 2020," the event’s organisers said on its website.
"Given the growing concerns over public health and safety due to the developing coronavirus (Covid-19) situation, the team has proactively made arrangements to move the planned programme to autumn 2020.
"Advertising Week prides itself on being an inclusive and accessible platform, and we felt it was critical to ensure it could be comfortably and safely attended by British, European and global delegates."
The statement added that a "revised agenda will be available soon" and "we are grateful to our partners for their ongoing support in making this collaborative decision and look forward to welcoming all delegates in person in September".
Matt Scheckner, founder of Stillwell Partners, set up Advertising Week in New York in 2004 and launched the Europe event in London in 2013, when he teamed up with Kathleen Saxton, founder of The Lighthouse Company.
Many media companies, including Google and Facebook, are among commercial supporters of Advertising Week Europe.
South by Southwest, due to take place in Austin, Texas, this month, was cancelled last week because of coronavirus concerns.