She acted in small roles in few
Vairam Nataka Sabha dramas. Once she went to see a drama of
S. S. Rajendran, who was residing at
Pudukkotai, in Tamil Nadu, and P.A. Kumar introduced her to Rajendran. She showed her skill in dialogue delivery and was offered a job in S.S.R. Nataka Mandram company and played in hundreds of stage productions all over the district: The dramas included
Manimagudam, Thenpandiveeran and
Pudhuvellam. She credits her work in
Manimagudam as where she was first recognized as an actress. She then took part in an unfinished film starring
S. S. Rajendran and
Devika. She migrated from dramas to the silver screen with the role of a heroine in the 1958 Tamil film
Malayitta Mangai:
Kannadasan gave her the lead role in this film. The first film in which she played the heroine was the 1963
Konjum Kumari. Then, she concentrated more on comedy from 1960. She was given equally challenging roles alongside the well known comedian Nagesh in 50 films. When asked in an interview as to how she got into films, she quoted, "It's all because of Kannadasan. It was he who changed my life by casting me in the film
Maalayitta Mangai in 1957. It was a comical role, and he trusted me so much and said that I will be able to pull it off. I was very doubtful about it, but he told me, "If you are going to act in films only as a heroine, people here will throw you out of the industry after three or four years, but doing such roles will take you places. And you have the talent, too, to reach higher peaks." That is when I got confidence and continued doing comedy roles." The first time Manorama stood before the camera was for a Sinhalese film
Sukumali in 1957, in which she played the heroine's friend. Her dance master Suryakala recommended her to the director Masthaan to play the role. She has acted predominantly in Tamil films since 1958, but also acted in Telugu, Hindi, Malayalam and Kannada movies as well. Her on-screen pair with Tangavelu was appreciated in the film
Vallvanakku Vallavan in 1965. Her on-screen pair with Nagesh was very popular in 1960–69 and then with Cho in the 1970s and 80s and later with Thengai Srinivasan, Vennira Aadai Moorthy, and Surali Rajan in the 70s and 80s. She had done playback singing for 300 songs, mostly pictured on herself, in Tamil films. The first song that she sang was in a film called
Magale Un Samathu, composed by
G. K. Venkatesh and this opportunity she got due to the film's producer P.A. Kumar. She has sung a classical-based song with TM Sounderajan in the film
Dharshinam (1970), where she was paired with Cho. Manorama sang a song with L.R. Eswari named "Thaatha thaatha pidi kudu". Her career's biggest hit song sung by herself was Vaa Vaathiyaare Uttaande composed by music director V. Kumar for the film ''Bommalattam", which was picturised on her and Cho. She also sang for
M. S. Viswanathan and
A. R. Rahman. Some of her best Tamil films include
Anbe Vaa,
Thenmazhi,
Ethir Neechal,
Galatta Kalyanam,
Chittukuruvi,
Durga Devi,
Annalakshmi and
Imayam. In Telugu, she starred in films such as
Rikshavodu,
Krishnarjuna and
Subhodayam. When asked in an interview as to which are her memorable roles, she said "It is Nadigan, which had Sathyaraj and Khushbu in the lead. I cannot forget that role of Baby Amma in my life. Also my role in
Chinna Gounder, for which I had to sport weird, artificial teeth, is something which I always think about. She acted alongside the well-known comedian
Nagesh in 50 films and in 20 films with Cho Ramaswamy. They made a notable pair and acted in many well-received comedies. In 1974 she shared the screen space with the legendary comedian Mehmood in the Hindi movie
Kunwara Baap. Cho and Manorama were paired together in 20 films which included
Malligai Poo, Annaiyum Pidhavum, Dharisanam, Anbai Thedi, Nanaivin Nindraval, Nirai Kudam, Aayiram Poi, Mohammed Bin Tughlaq, Bommalattam, Delhi Mappilai, Vilayattu Pillai, Kanavan, Rojavin Raja and
Suryagandhi. The character she was given by
K. Balachander in the 1989 film
Unnal Mudiyum Thambi she personally considers a cornerstone as she was giving a new challenge as an actor. She related in an interview on Toronto TV that one of the most challenging characters she played was the role of the 50-year-old unmarried woman in the 1990 film
Nadigan with
Sathyaraj. She has acted with all of the lead comedians across five different generations, which includes
M. R. Radha,
K. A. Thangavelu,
J. P. Chandrababu, A. Karunanithi,
Ennatha Kannaiya,
V. K. Ramasamy,
Nagesh,
Cho Ramaswamy,
Thengai Seenivasan,
M. R. R. Vasu,
Suruli Rajan,
Vennira Aadai Moorthy,
Janagaraj,
Pandiarajan,
Goundamani,
Senthil,
Vivek and
Vadivelu. She has been in films with six chief ministers. She played the female lead in the plays written, directed and acted by
C. N. Annadurai, former chief minister of Tamil Nadu. She has also appeared in plays with another chief minister of Tamil Nadu,
M. Karunanidhi. She has acted in films with
MGR,
J. Jayalalithaa and Vijay, who all later became chief ministers of Tamil Nadu later. She has also acted in Telugu films with Dr.
N. T. Rama Rao, who became the chief minister of Andhra Pradesh. She also acted with
Vijay (actor) in
Rasigan and
Senthoorapandi. When asked which character of hers she found most hilarious to play, she specified the role of a talkative female, who is forced to act dumb in a film called
Unakkum Vazhvu Varum. She had played this role along with Thengai Srinivasan. She was bitten by a Bungarus fasciatus/ Kattuviriyan snake during the shooting of
Manjal Kungumam and was admitted to hospital. Coincidentally, after recovery, the next scene, she had to act was in
Aadi Viradham, where she had to bathe a snake statue and sing a lullaby for it, and the director asked her whether she would like to perform and she replied "Yes very much!" and she did the film. Manorama, being a close friend of Jayalalithaa and of the firm belief that Jayalalithaa would never be corrupt, campaigned against actor Rajinikanth in support of Chief Minister Jayalalithaa in the 1996 elections. When asked as to how she was able to do more than 1500 films, she said in her interview in September 2015, "I believe I am a blessed person. Without God's will, I couldn't have acted in so many films. It all just happened in my life, and you won't believe it, but I still have the urge to act. The one person who is the reason for all my success is my mom. She did everything for me in life, and I miss her the most now (she breaks into tears). Whatever I achieve or have achieved in life is only because of her." She supported young talents and budding directors in her old age. In 2013 she acted in a Tamil short film named
Thaaye Nee Kannurangu, directed by LGR Saravanan. She acted as a cancer patient and a mother of Mr. Srikanth. ==Death==