Find out all the details you need to know on Wales' qualifying group below.
Ireland rank at No.33 in the current rankings, while Serbia, Georgia and Moldova are 54th, 137th and 159th respectively.
Qualifying gets under way on Monday 5th September 2016.
The new Football League season starts on 5th August and the Premier League gets going eight days later, meaning the international break will arrive after the fifth and third matchdays respectively.
Wales' fixture list for World Cup qualifying is as follows.
Wales' Euro 2016 adventure is over after a 2-0 defeat to Portugal.
Cristiano Ronaldo and Nani struck in the second half in Lyon last night to consign Chris Coleman's side to a semi-final exit after a tournament in which Wales captured the imagination of a nation.Wins over Russia and Belgium, in particular, will live long in the memory from a tournament where the Dragons offered hope and restored faith in the future of Welsh football.And they won't have too long to lick their wounds as their 2018 World Cup qualifying campaign gets underway soon.Moldova (H) - Monday 5th September 2016: 7.45pm Austria (A) - Thursday 6th October 2016: 7.45pm Georgia (H) - Sunday 9th October 2016: 5.00pm Serbia (H) - Saturday 12th November 2016: 7.45pm Republic of Ireland (A) - Friday 24th March 2017: 7.45pm Serbia (A) - Sunday 11th June 2017: 7.45pm Austria (H) - Saturday 2nd September 2017: 7.45pm Moldova (A) Tuesday 5th September 2017: 7.45pm Georgia (A) - Friday 6th October 2017: 5.00pm Republic of Ireland (H) - Monday 9th October 2017: 7.45pm Each group winner will qualify directly for the World Cup.From the nine group runners-up, the eight best runners-up will advance to the play-offs, where they will be drawn into four home-and-away ties, while the ninth will be eliminated.The winner of each tie will also qualify, meaning 12 European countries qualify in total.