Ferrell, who played housekeeper Berta on the longtime sitcom, died of cardiac arrest on Monday.
Tributes were paid to the actress. who starred alongside Jon Cryer, Angus T Jones and Charlie Sheen, and later Ashton Kutcher, on the popular show.
Sheen, who was fired from Two and a Half Men in 2011, tweeted a photo of him and Ms Ferrell on set and described her as “an absolute lover, a consummate pro. [and] a true friend. A shocking and painful loss ”.
He added: “Berta, your housekeeper was a bit suspicious, the management of your ‘people’ was perfect. ”
Cryer, who played Sheen’s goofy onscreen brother, recalled meeting Ferrell on set for the first time and said he was already a fan of his work.
He tweeted: “She was a beautiful human, Berta’s gruff exterior was an invention of the writers. [Her] warmth and vulnerability were his real strengths.
“I cry for the woman I will miss, and the joy she brought so much to her.
Two and a Half Men co-creator Chuck Lorre said, “We called her Chatty. And we all loved him.
“Twelve years of ups and downs, and lots of laughs. Through it all, she was a rock. One of the biggest. I had the privilege of calling her a friend. ”
Lee Aronsohn, who created the show alongside Lorre, described Ms Ferrell as “a warm and wonderful woman who was always a joy to be on set.”
He added: “My heart goes out to her husband Arnie, who has always been by her side. ”
The show aired for 12 seasons between 2003 and 2015.
Film actress Viola Davis also paid tribute to him.
She tweeted: “RIP Conchata Ferrell. I loved not only working with you, but also getting to know you… your humor, your heart, your talent, how much you loved your daughter and your husband… Thank you for honoring us with your presence. ! ”
For his role as Berta, Ferrell won two Emmy nominations.
His film roles include the 1976 satirical comedy Network, Edward Scissorhands by Tim Burton and Erin Brockovich, the 2000 biopic starring Julia Roberts.