The Spaniard left his role as Los Blancos manager earlier this week after just seven months in charge and the England midfielder has slammed claims that there was tension between him and his manager.
Bellingham wrote on his JB5 app: "Until now I’ve let far too many of these [reports] slide, always hoping the truth will come to light in its own time.
"But honestly… What a load of s***. Truly feel sorry for the people that hang on to the every word of these clowns and their ‘sources’.
"Do not believe everything you read. Every now and then, these lot need to be held accountable for spreading this kind of damaging misinformation for clicks and added controversy."
Bellingham's team-mate Kylian Mbappe is another rumoured to have fallen out with Alonso but thanked his manager on social media when his exit was announced on Monday (12.01.26).
He wrote in an Instagram Story: "It's been short but it was a pleasure to play for you and learn from you.
"Thank you for giving me the confidence since day one. I will remember you as a manager who had clear ideas and knows many things about football. Best of luck for your next chapter."
Alonso - who represented the La Liga giants as a player for five years - replaced Carlo Ancelotti at Real last summer and initially made a strong start as boss, although disappointing recent results saw the team slip behind Barcelona in La Liga and the 3-2 Spanish Super Cup final defeat to the Catalan side on Sunday (11.01.26) proved to be his last game in charge.
A club statement said: "Xabi Alonso will always have the affection and admiration of all Madrid fans because he is a Real Madrid legend and has always represented the values of our club. Real Madrid will always be his home.
"Our club thanks Xabi Alonso and his entire coaching staff for their work and dedication throughout this time, and wishes them the best of luck in this new stage of their lives."
Alonso has been replaced as manager by ex-Real defender Alvaro Arbeloa, who has been promoted after coaching the club's B team.