Kenyan Joel Kipsang will aim to secure a record fourth Belfast Marathon success on Monday 7 May.
The 30-year-old first took victory in 2013, beating compatriot James Rotich in 2 hours 19 minutes 28 seconds.
Kipsang followed that up with a second win in 2015 in a similar time and achieved his treble the following year with a win over Eric Koech in 2:17.39.
Another Kenyan, Dan Tanui, is among the major threats, having finished second in 2017 and third in 2016.
The 32-year-old's time of 2:17.40 12 months ago would have been enough to secure victory most years but he had to settle for second place behind Bernard Rotich, who won in 2:16.02, the third fastest time ever.
Tanui is part of the Ciaran Collins ' Project Africa team designed to provide opportunities for up and coming runners.
Kipsang hails from the Rift Valley area of Africa which has historically produced many world class runners and considers Belfast as his favourite event.
On two occasions he has made key breaks for the lead on Corporation Street with only three miles remaining but next week could be the last time he will be able to do this as significant course changes are proposed for next year's event.
The women's race will see the return of Radka Churanova of the Czech Republic, the 40-year-old having finished third in 2016 and fourth one year ago behind local winner Laura Graham.
Close to 17,000 participants are expected to set off from Belfast City Hall to compete in the marathon and wheelchair race, marathon team relay, 8-mile walk and Fun Run.
The 26.2-mile marathon sees a big surge in the number of entries this year, with around 3,000 expected to take part.
2018 has also seen an increase of Team Relay participants, with around 2,200 'five person' relay teams participating.