Thiam and Barshim each won world titles in London this year. The 23-year-old Thiam opened the year by taking the European indoor pentathlon title then she climbed to third on the heptathlon all-time list with a performance of 7,013 points at a meeting in Gotzis, Austria, in May.
The 26-year-old Barshim completed an undefeated season across 11 competitions and won the Diamond League title. He became the first high jumper in history to leap 2.40 meters or higher in five successive years.
IAAF president Lord Sebastian Coe says, "I'm particularly excited by the young generation of talent which so dramatically came of age on the world stage in 2017. Athletics looks forward to a strong and exciting future safe in your hands."