The Ibanez Tube Screamer is an overdrive pedal made by Ibanez. First developed by Maxon as a competitor to the Boss OD-1, the Tube Screamer was sold outside of Japan under the Ibanez brand name and became popular among guitarists for its characteristic midrange-boosted tone and amp-like distortion. The Tube Screamer has gone through multiple iterations since its debut in 1979, notably the original TS808 model and its successor, the TS9. Many guitarists have used it to create their signature sound, and it is considered one of the most successful, widely copied, and modified overdrive pedals in the history of the electric guitar.

The Tube Screamer has a drive knob, a tone knob, and a level knob. The drive knob adjusts gain (which can affect the amount of distortion), the tone knob adjusts treble frequencies, and the level knob adjusts the output volume of the pedal. The pedal also provides a boost to midrange frequencies and helps reduce muddiness by cutting bass frequencies. Many guitarists prefer this sort of equalization, as it helps keep their guitar from getting lost in the overall audio mix. This, along with its versatility as a simple distortion, has made the pedal popular for a wide variety of musical styles.

In the late 1960s and early 1970s, Ibanez and its parent company, Hoshino Gakki, were best known for producing their own branded copies of guitars made by Gibson, Fender, and Rickenbacker. By the middle of the decade, Ibanez began adding effects pedals to their product line and wished for a model to compete with the Boss OD-1. Nisshin, the Japanese company contracted to make the pedals, first produced the "Overdrive," commonly known as the "Orange Overdrive" due to its color. It used a now-standard three-control format (in this case, Level, Balance, and Distortion) and was housed in a casing similar to the later 808 design. The OD-855 Overdrive II followed, adopting the green color and square footswitch characteristic of the 808. While both pedals could produce overdrive-type distortion at lower gain levels, at higher settings the Overdrive became fuzz-like, and the OD-855 had a significant low-end emphasis.

The original Tube Screamer circuit was created in 1979 by Nisshin engineer Susumu Tamura, who wished to design a pedal that better emulated the effect of playing an overdriven tube amp. As Boss owned the patent for solid-state asymmetrical clipping, Tamura was forced to use a symmetrical clipping design, and rejected several op amps for being too expensive before settling on the JRC 4558D integrated circuit (IC) chip. For audio tests, Tamura used a 1968 Fender Twin Reverb and a Vibrolux Reverb, and occasionally a Marshall 1959 Super Lead.

Tamura's finished design, the OD808 Overdrive Pro, was first sold under Nisshin's Maxon label, as the arrangement with Ibanez allowed Nisshin to sell the same pedal designs under their own brand. However, because Maxon could not export products, they sold the OD808 only domestically. The "Tube Screamer" name was born when Tamura and Hoshino took an OD808 to Sam Ash Music in Manhattan, where Sammy Ash—the company founder's grandson—remarked that the pedal sounded like a "screaming tube amp" and noted that the Dunlop Cry Baby wah-wah pedal was so-named for sounding like a crying baby. As a result, the OD808 was renamed the TS808 Tube Screamer Overdrive Pro for international sales through the Ibanez brand name.

The Tube Screamer has gone through many variations since its debut:

Once Ibanez discontinued the 9 series pedals, they introduced the "Master" or "L" series. These were only made in 1985, and did not have the Tube Screamer in the line-up.

A rare version of the Tube Screamer was the ST9 Super Tube Screamer, which was sold only in Europe.