Twitter co-founder Evan Williams, who now leads online publishing platform Medium, is among the first batch of speakers lined up for this year's Web Summit, which returns in November.
Other speakers announced are Stripe co-founder John Collison, European Commissioner for Competition Margrethe Vestager, Tinder co-founder Sean Rad, Game of Thrones star Maisie Williams and Samsung Electronics president Young Sohn.
They will be among 1,200 speakers who will be addressing more than 70,000 attendees at the event, which takes place in Lisbon for the third successive year.
Among the other speakers announced on Tuesday are the chief executives of Ebay, Tommy Hilfiger, Allianz, Axa, Booking. com, Etihad Airways and Air Asia.
The Irish-founded tech conference started in Dublin in 2009 with less than 400 attendees. It moved to Lisbon in 2016. Its current deal with the Portuguese government, which sees the event organisers being paid €1.3 million each year to host the conference, end this year.
While the company has the option of a two-year extension, it is believed that co-founder and chief executive Paddy Cosgrave is in negotiations with a number of potential bidders over where the 2019 event will be held.
