Eleven first-time novelists appear on the 20-strong list, alongside four previously shortlisted authors.
Among the seven nationalities on the list is Petina Gappah, the first Zimbabwean author to be longlisted in the prize's 21-year history.
The shortlist will be revealed on 11 April, with the winner named on 8 June at London's Royal Festival Hall.
Kate Atkinson's Costa novel prize-winning A God in Ruins and Booker-shortlisted A Little Life by Hanya Yanagihara also make the cut.
"Over half the longlist is composed of first novelists. What excites me is the mixture of well-known and less well-known writers," said author Elif Shafak, one of this year's judges.
"It shows the flexibility and the strength of the prize. It is a very encouraging sign for new writers of all ages."
Eleven is the highest number of first novels to have been longlisted for the prize and has only happened once before, in 2000.
The authors who have previously been shortlisted are Kate Atkinson (2013), Anne Enright (2012), Attica Locke (2010) and Elizabeth Strout (2000).
Lawyer and businesswoman Margaret Mountford, chair of judges, said there were "a great many strong novels in contention".
She said: "We are delighted with the quality, the imaginative scope and the ambition of our chosen books, a longlist which reflects the judges' interests and tastes. We hope readers will enjoy the variety of outstanding work on offer."
Joining her and Shafak on the judging panel are journalists Naga Munchetty and Laurie Penny and writer and singer Tracey Thorn.
Formerly known as the Orange Prize, the book award was set up in 1996 and is awarded for the best full-length novel of the year written by a woman and published in the UK.
The winner will receive a cheque for Â£30,000 and a limited edition bronze known as a Bessie.
Last year's winner was Ali Smith for How to be Both (2015).
Debut writers dominate the longlist for this year's Baileys Women's Prize for Fiction.