The ICC rankings released today revealed Labuschagne had achieved top spot for the first time in his career since making his debut in 2018 against Pakistan.
The Queensland batsman has made a strong start in the Vodafone Ashes Test series, scoring a century and two half centuries so far in the first two matches won by Australia.
Queensland Cricket CEO Terry Svenson said his Test batting achievements deserved applause for inspiring a generation of boys and girls to play cricket.
"Marnus continues to excel on the international stage and like his many fans and supporters, we have enjoyed celebrating his achievements."
"It is also rewarding to see him continue to retain his close ties to the grassroots where he started his playing career,'' he said.
"He is generous with his time when he plays for Redlands in the KFC Queensland Premier Cricket competition, and provides great insights and guidance for young players and indeed fans."
"Marnus is always striving to find ways to further develop his playing and leadership skills, both on and off the field, and we admire these strong, proactive qualities in him."
"We wish Marnus every success in the remainder of the Ashes series as Australia seek to retain the trophy."
Labuschagne is currently in Melbourne preparing for the Boxing Day Test.