Held at a ceremony on London on Wednesday, the award is decided by a panel of international handicappers based on the horse's best performance of the year.
Winx stretched her unbeaten run to 29 with another clean sweep through 2018 which included seven wins, all at Group One level and a historic fourth Cox Plate however her year high rating of 130 came in winning the Queen Elizabeth Stakes at Randwick in April.
Winx after her win in the Queen Elizabeth Stakes - the equal highest rated performance in the world for 2018
Cracksman earned his equal top rating of 130 when winning the QIPCO Champion Stakes for the second consecutive year in a season which saw him finish with three wins and a second from four starts before retiring to stud,.
Winx was the second ranked in the World's Best Racehorse rankings in 2017 with a rating of 133, one point behind Arrogate's 134 and in 2016 was ranked third behind Arrogate and California Chrome.
She becomes the second Australian horse to top the world rankings with Black Caviar also the joint winner in 2013.
The New Zealand bred Hong Kong champion Beauty Generation was also heralded with a rating of 127 ranking him number four in the world.
The World's Top Ten in the Longine's World's Best Racehorse Rankings for 2018.
1: 130 – Winx (Aus)
1: 130 – Cracksman (GB)
3: 128 – Accelerate (USA)
4: 127 – Beauty Generation (NZ)
4: 127 – Gun Runner (USA)
4: 127 – Roaring Lion (USA)
7: 126 – Poet's Word (Ire)
8: 125 – Crystal Ocean (GB)
8: 125 – Enable (GB)
8: 125 – Justify (USA)
