The soap legend first joined the long-running BBC soap as chain-smoking launderette worker Dot Cotton in 1985.
Adam Woodyatt, who played Ian Beale, led the tributes to his EastEnders co-star.
He wrote: “I’m lost for words, something June never was. So many memories, so much fun. Just purely and simply an incredible woman who had the most incredible life and career, I was fortunate to have shared a small part of it. They never made you a Dame (we did try), but to me you will always be Dame Brown.”
EastEnders bosses also paid tribute to the star who they said was “loved and adored by everyone” on set.
A spokesperson for EastEnders said: “We are deeply saddened to announce that our beloved June Brown, OBE, MBE sadly passed away last night. There are not enough words to describe how much June was loved and adored by everyone at EastEnders, her loving warmth, wit and great humour will never be forgotten.
“June created one of the most iconic characters in Dot Cotton, not just in soap but in British television, and having appeared in 2884 episodes, June’s remarkable performances created some of EastEnders finest moments.
“We send all our love and deepest sympathies to June’s family and friends. A very bright light has gone out at EastEnders today – we shall all be raising a sweet sherry in June’s memory. Rest in peace, our dearest June. You will never be forgotten.”
The actress died at her home in Surrey on Sunday with her family by her side.
Confirming her passing in a statement, they said: “We are deeply saddened to announce our beloved mother, June, passed away very peacefully at her home in Surrey on Sunday evening, with her family by her side.
“We would kindly ask that our privacy is respected at this very difficult time.”
Brown took a break from filming EastEnders between 1993 and 1997.
She announced the bombshell news of her exit in 2020 with little fanfare, revealing her decision on a podcast with a former co-star.
Dot had not featured in the soap for a month, when she left a voicemail for Sonia Fowler saying she had moved to Ireland.