Tiran Calvin Porter (born September 26, 1948) is an American bass and guitar player, vocalist and composer, best known as a member of The Doobie Brothers from 1972 to 1980 and 1987 to 1992.

His replacement was session man Willie Weeks, later famous for his collaboration with Michael Jackson and other Quincy Jones protégés.

More recently, Porter played bass with singer-songwriter Keith Greeninger from Santa Cruz, California, Beatles tribute band White Album Ensemble,[4] Stormin' Norman and the Cyclones,[5] and Moby Grape during its occasional reunions.

[6] Porter's most notable contributions to the Doobie Brothers' sound were his busy and punchy bass lines; his distinctive tone permeates all of the band's classic compositions and hits.

The hit title track from Takin' It to the Streets, which prominently features Porter's thundering, picked notes, is a prime example of this technique.