"Mouth" is a song written by Australian singer-songwriter Merril Bainbridge and produced by Siew for Bainbridge's debut album, The Garden (1995). It was released as the album's first single in October 1994 in Australia, then was re-issued in 1995. "Mouth" became her biggest hit, peaking at number one on the Australian ARIA Singles Chart for six consecutive weeks and in Canada for one week. The song also became a top-five hit in Iceland and the United States and reached number 17 in New Zealand.

The song, a playful and suggestive tune, was often referred to having something related to sexual themes. Bainbridge stated that "(Any sexuality on "Mouth" was) not deliberate—it was definitely not a sexual song. It's just honest—about a relationship, how you feel in a relationship. Sometimes you feel you're in control and the next thing, you're insecure—it's the role playing thing. To me, it's not about straight up sexuality. It doesn't bother me if people connect with that, because obviously it's there, but it wasn't something I was aware of".^[1]

There were two music videos for the song, both directed by Gotham Records co-founder Ross Fraser.^[2] The first video is a simple video with no plot, shot in both black and white and colour. Scenes included Bainbridge flirting with a long-haired man in a car and singing to camera wearing a black lingerie dress with a red heart in the middle of it, intercut with shots of another man's mouth. This video was released in Australia. The second video is in black and white and is just the footage of Bainbridge in the car kissing the first man for the whole video, looking at the camera three times. It was filmed along Yarra Boulevard in the Melbourne suburb of Kew.^[3] This video as well as the first, was released around the world. The first music video can be found on the special edition of The Garden as a CD-ROM.

The "Mouth" single was first released in Australia in October 1994 but disappeared quickly due to lack of interest and airplay, charting outside the top 100.^[4] The song was repackaged and reissued in 1995 and with the help of airplay and more promotion it became the biggest song of her career. The single belatedly entered the Australian ARIA top 100 in March 1995 at number 60,^[5] and during its ninth week on the chart,^[6] it reached the number-one position and stayed there for six consecutive weeks.^[7] By doing so, Bainbridge became the first Australian woman to top her native country's chart with a self-penned debut single.^[8] "Mouth" spent a total of 26 weeks in the charts,^[9] was the fourth-highest-selling single for 1995,^[9] and was accredited platinum by ARIA.^[9] The song was nominated for seven ARIA Awards in 1995 but failed to win any.^[10]

In the United States, "Mouth" debuted on the Billboard Hot 100 at number 67, eventually peaking at number four. Success in the American music industry was, and still is, a relatively rare occurrence for Australian artists and the success of "Mouth" in the US gave Bainbridge superstar status in her home country for a period. Ross Fraser stated that he thought she would have had more chance of success in Europe and what happened in the US came as a surprise.^[11] The song spent a total of thirty weeks in the US charts and was the 37th-highest-selling single for 1996. It was accredited gold by RIAA selling 600,000 copies around the US.^[12][13] After the success of the song, Bainbridge toured the US and during that tour she played at Madison Square Garden in New York City with Sheryl Crow. The song did not enjoy the same success in the UK, peaking at 51 in the charts during its eight-week run in the top 200. The song also went top five in Japan, Hong Kong and the Philippines.^[14]