Festival director Nick Barley, now in his second year, said the festival had maintained its focus on "quality" rather than chasing celebrities.
"Literature is the key part of it. If we went too far down the celebrity line we would lose what we are really all about.
"Nevertheless, there are some well-known names coming along. Pamela Stephenson Connolly and Alexei Sayle are coming, not because they are celebrities, but because they have great stories to tell.
"They can be seen alongside world-famous novelists and poets such as Carol Ann Duffy and AS Byatt."
Also speaking today will be Booker Prize winner and Scottish author Ali Smith, and Caitlin Moran, whose book How To Be A Woman raced up the Amazon book charts upon its release earlier this year.
The EIBF runs until 29 August.