Afghanistan's President Hamid Karzai, Pakistani Prime Minister Shaukat Aziz, and Israeli Foreign Minister Tzipi Livni are among those expected to attend the three-day meeting in the Dead Sea resort of Shuneh.
Organizers say the theme of this year's forum is "putting diversity to work" in order to accelerate economic growth and promote regional peace.
Meetings at the forum are expected to include discussions of ways to end the conflict between the Israelis and Palestinians.
King Abdullah hosted Israeli Prime Minister Ehud Olmert earlier this week to discuss an Arab peace plan.
A meeting of the G11 group of developing countries is due to be held on the sidelines of the forum on May 19.
The G11 brings together Croatia, Ecuador, Georgia, Honduras, Indonesia, Jordan, Morocco, Pakistan, Paraguay, Sri Lanka, and El Salvador.
The group says it is dedicated to reducing the debt owed by its member states, alleviating poverty, and raising standards of living.
King Abdullah announced the establishment of the G11 last September.