Todd Harry Rundgren (born June 22, 1948) is an American musician, singer, songwriter, and record producer who has performed a diverse range of styles as a solo artist and as a member of the bands Nazz and Utopia. He is known for his sophisticated and often unorthodox music, his occasionally lavish stage shows, and his later experiments with interactive art. He also produced music videos and was an early adopter and promoter of various computer technologies, such as using the Internet as a means of music distribution in the late 1990s.

A native of Upper Darby, Pennsylvania, Rundgren began his professional career in the mid-1960s, forming the psychedelic band Nazz in 1967. After two years, he left Nazz to pursue a solo career and immediately scored his first US top 40 hit with "We Gotta Get You a Woman" (1970). His best-known songs include "Hello It's Me" and "I Saw the Light" from Something/Anything? (1972), which get frequent air time on classic rock radio stations, the 1978 "Can We Still Be Friends", and the 1983 single "Bang the Drum All Day", which is featured in many sports arenas, commercials, and movie trailers. Although lesser known, "Couldn't I Just Tell You" (1972) was influential to many artists in the power pop genre. His 1973 album A Wizard, a True Star remains an influence on later generations of bedroom musicians.

Rundgren is considered a pioneer in the fields of electronic music, progressive rock, music videos, computer software, and Internet music delivery. He organized the first interactive television concert in 1978, designed the first color graphics tablet in 1980, and created the first interactive album, No World Order, in 1993. Additionally, he was one of the first acts to be prominent as both an artist and producer. His notable production credits include Badfinger's Straight Up (1971), Grand Funk Railroad's We're an American Band (1973), the New York Dolls' New York Dolls (1973), Meat Loaf's Bat Out of Hell (1977), and XTC's Skylarking (1986). He was inducted into the Rock and Roll Hall of Fame in 2021.

Todd Harry Rundgren was born in Philadelphia on June 22, 1948, the son of Ruth (née Fleck; April 29, 1922 – April 6, 2016) and Harry W. Rundgren (1917–1996). His father was of Swedish descent and his mother was of Austrian and German descent. He grew up in the bordering town of Upper Darby Township, Pennsylvania and taught himself how to play guitar with little help. As a child, Rundgren was fascinated by his parents' small record collection, which consisted of show tunes and symphonic pieces, and especially by the operettas of Gilbert and Sullivan. Later, he grew infatuated with the music of the Beatles, the Rolling Stones, the Ventures, and the Yardbirds, as well as the Philadelphia soul of Gamble & Huff, the Delfonics, and the O'Jays. At the age of 17, he formed his first band, Money, with then-best friend and roommate Randy Reed and Reed's younger brother.

After graduating from Upper Darby High School in 1966, Rundgren moved to Philadelphia and began his career in Woody's Truck Stop, a blues rock group in the style of Paul Butterfield Blues Band. Rundgren stayed with the band for eight months, and in the process, they became the most popular group in Philadelphia. He and bassist Carson Van Osten left before they released the eponymous first album to form the rock band Nazz in 1967. By then, Rundgren had lost interest in the blues and wanted to pursue a recording career with original songs in the style of newer records by the Beatles and the Who. As a member of the Nazz, he learned his craft as a songwriter and vocal arranger, and was determined to equal the artistry of the Beatles.

In 1968, after recording four demo discs, the Nazz were signed by Atlantic Records subsidiary Screen Gems Columbia (SGC). They were flown to Los Angeles to produce their first album at ID Sound studio. Rundgren had no prior production experience and remembered that the producer, Bill Traut, "just whipped through the mixes in a day or two ... So I got it into my head, 'Well, he's gone now, so why don't we just mix it again, more like the way we want it?' Our engineer didn't mind if we went and just started diddling around on the board ... It was pretty much trial and error." He took an experimental approach to the recordings, employing techniques such as varispeed and flanging, and despite having no formal training, scored music charts for string and horn arrangements. Engineer James Lowe, whom Rundgren recruited for his involvement with arranger Van Dyke Parks, believed that Rundgren had become the de facto leader of Nazz, and that a producer's credit was wrongfully withheld from him.

Nazz gained minor recognition with their debut single, July 1968's "Open My Eyes" backed with "Hello It's Me", both songs penned by Rundgren. They subsequently released three albums: Nazz (October 1968), Nazz Nazz (April 1969), and Nazz III (1971). In March 1968, New York singer-songwriter Laura Nyro released her second album, Eli and the Thirteenth Confession. When Rundgren heard the record, he was struck by "all the major seventh chords and variations on augmented and suspended chords", and it had an immediate impact on his songwriting, especially as he began to compose more on piano. He elaborated:

I know for a fact that her influences were the more sophisticated side of R&B, like Jerry Ragovoy and Mann & Weil and Carole King. ... and she also had her own very original and very jazz-influenced way of seeing things. It was that extra layer that made her influential. A lot of those chords she got from other people. But beyond the elements of her composition, I always thought it was the way she played her own material that really sold it. ... I met her right after Eli and the Thirteenth Confession. I actually had arranged a meeting, just because I was so infatuated with her and I wanted to meet the person who had produced all this music. ... after I met her the first time, she asked me if I wanted to be her band leader. But the Nazz had just signed a record contract and I couldn't skip out on the band, even though it was incredibly tempting.