The shocking death has rocked the U.K. entertainment industry and tributes have since flooded in for Mayall, who established himself as a stand-up star in comedy troupe The Comic Strip, a group which also featured his college pal and future professional partner Adrian 'Ade' Edmondson and Dawn French and Jennifer Saunders.
He rose to national fame as one of four students sharing a house in hit sitcom The Young Ones in 1982 and went on to enjoy a slew of iconic roles, including as a mean-spirited politician in The New Statesman and an arrogant military officer in Rowan Atkinson's comedy Blackadder. He also re-teamed with Edmondson to play a pair of hopeless single men in slapstick show Bottom.
Fellow funnyman Walliams was among the first to take to Twitter.com to express his sadness at Mayall's loss, sharing a video clip of his role in Blackadder and writing, "I am heartbroken that my comedy idol growing up Rik Mayall has died. He made me want to be a comedian."
Simon Pegg simply posted YouTube footage of Mayall in The Young Ones with fans, while Brand tweets, "And all the grown-ups will say, 'But why are the kids crying?' And the kids will say, 'Haven't you heard? Rick (sic) is dead' Rip".
Irish actor O'Dowd adds, "Very sad to hear about Rik Mayall's passing. 'Bottom' was a huge part of my youth", and director Edgar Wright posts, "Shocked and saddened that a comedy hero is gone; for those who grew up on The Young Ones, Rik Mayall was one of funniest performers ever."
Monty Python veteran Idle tweets, "Very sad to hear of the passing of Rik Mayall. Far too young. A very funny and talented man", and Blackadder producer and writer John Lloyd tells the Bbc, "It's really a dreadful piece of news. He was the most extraordinarily good actor as well as being an amazing stand-up comics. Apart from being great company, he was a great professional."
Meanwhile, his close friend Edmondson has also issued a statement about the years they spent working together, declaring, "They were some of the most carefree, stupid days I ever had and I feel privileged to have shared them with him."
Mayall's cause of death has yet to be determined, but a spokesman for Scotland Yard police reveals paramedics were called to the comedian's house in Barnes, south-west London at 1.20pm local time, when "a man, aged in his 50s, was pronounced dead at the scene". His passing is not believed to be suspicious.
His death comes 16 years after the comedian was left in a coma for several days in 1998 following a quad bike accident near his home in south-west England. He survived the scare but suffered memory problems as a result of the crash.
In recent years, Mayall had concentrated mainly on voiceover work and Tv shorts.