2011
Her first role after graduation was the lead role of Sarah in the musical Dance of the Vampires at the Imperial Garden Theater. On November 25, it was announced that Takahashi was cast for a stage play titled La Patisserie, which ran from March 3 to March 11 in Tokyo, March 20 in Osaka, and March 22 in Ishikawa.
2012
On May 6, Takahashi announced that she had been cast in the Taiga drama Taira no Kiyomori. She played Tsuneko, the wife of Kiyomori's eldest son. From September 12 to September 23, she starred in a stage play titled High School Uta Gekidan☆Otoko-gumi. It was announced that Takahashi would voice a character in the hit anime series Detective Conan, with her episodes airing in early 2013.
2013
On February 12, Hello! Project Fanclub News announced that Takahashi would star in a stage play titled Moshimo Kokumin ga Shusho o Erandara along with Rika Ishikawa, S/mileage members Ayaka Wada and Kanon Fukuda, and Juice=Juice members Karin Miyamoto and Akari Uemura. The play ran for 11 performances from April 24 to April 30. On March 18, Takahashi appeared in the commercial “Ai to Kumao” to promote the insect repellent Mushuda; it was her first time appearing solo in a commercial. On May 10, Takahashi modeled for the Vanquish Venus fashion magazine. On July 3, it was announced that she would be going to Thailand for Japan Festa 2013 from August 31 to September 1. She held a free mini live and handshake event. On July 16, she announced two live birthday concerts to be held on September 14 (Tokyo) and 16 (Osaka), titled called "Ai Takahashi Birthday Live 2013 ~HELLO♥27~", but the Osaka performance was cancelled due to a typhoon. On July 21, Takahashi held a live solo performance titled "Takahashi Ai Sparkling Live in Yuigahama". On September 10, HMV announced that Takahashi would be releasing her first style book on October 18, titled "AI am I", which would include an interview about her Morning Musume days, as well as her ideas about love. It would also include articles on fashion, hair tips, and makeup. Takahashi became a regular on the new TV drama Jikken Keiji Totori 2, which began airing on October 12. In November, Takahashi was cast in the musical Merrily We Roll Along. From late October to November, Takahashi began filming for the movie Kara-age☆USA, starring in the main role. The movie was filmed in Oita, Japan and in the United States.
2014
On March 17, Takahashi appeared in another commercial for the insect repellent Mushuda, titled "Live." In September, her film Kara-age☆USA was released in theaters. On September 13, Takahashi released her second style book I have AI.
2015
Takahashi attended "Hello Pro Kenshuusei Happyoukai 2015 ~Haru no Koukai Jitsuryoku Shindan Test~" as a judge. In April, it was announced that she had joined a girl group with fellow Morning Musume graduates Yaguchi Mari and Tsuji Nozomi called "Datsumo Musume", under the management of Datsumo Labo, for the promotion of their hair removal services. On July 17, the women's lingerie and clothing retailer PEACH JOHN announced they would be collaborating with Takahashi for the collection "LOVE & PEACH". On September 11, it was announced that Takahashi would be collaborating with fashion brand Haco for the LOVE&PEACE Project 2015, a project that began in the wake of the 9/11 attacks to raise funds to support "a happy future for children around the world" by selling clothing from the project collection. On October 2, Takahashi modeled for a new boot collection by ASBee.
2016
In spring 2016, Takahashi starred in Hoshi Boshi no Yakusoku, Japan's first live-action film made for a Fulldome Cinema, which was screened in her hometown's Fukui City Museum of Natural History Dome Theater.