A telephone line or telephone circuit (or just line or circuit within the industry) is a single-user circuit on a telephone communication system. Typically this refers to the physical wire or other signaling medium connecting the user's telephone apparatus to the telecommunications network, and usually also implies a single telephone number for billing purposes reserved for that user.

In 1876 the earliest lines were single electrically conducting metal wires directly connecting one telephone to another with the Earth forming the return circuit. Later in 1878 the Bell Telephone Company began to use two-wire circuits (called the local loop) from each user's telephone to end offices which performed any necessary electrical switching to allow voice signals to be transmitted to more distant telephones.

These wires were typically copper, although aluminium has also been used, and were carried in balanced pairs separated by about 25 cm (10") on poles above the ground, and later as twisted pair cables. Modern lines may run underground, and may carry analog or digital signals to the exchange, or may have a device that converts the analog signal to digital for transmission on a carrier system.

Jeffrey "Jeff" Lynne (born 30 December 1947) is an English songwriter, composer, arranger, singer, multi-instrumentalist, and record producer who gained fame as the leader and sole constant member of Electric Light Orchestra. He was later a co-founder and member of The Traveling Wilburys together with George Harrison, Bob Dylan, Roy Orbison, and Tom Petty. Lynne has produced recordings for artists such as The Beatles, Brian Wilson, Roy Orbison, Dave Edmunds, Del Shannon and Tom Petty. He has co-written songs with Petty and also with George Harrison, whose 1987 album Cloud Nine was co-produced by Lynne and Harrison. Among the many compositions to his credit are such well-known hits as "Livin' Thing", "Evil Woman", "Turn to Stone", "Do Ya", "Xanadu", "Strange Magic", "Sweet Talkin' Woman", "Telephone Line", "Shine a Little Love", "Mr. Blue Sky", "Hold On Tight", "All Over the World", and "Don't Bring Me Down".

In 2008, The Washington Times named Lynne the fourth greatest record producer in music history.