He died in hospital on Monday of natural causes, his family said in a statement released by publicist Victoria Lord.
Known for his evocative lyrics and melodic compositions, Lightfoot received five Grammy nominations over the years and won 17 Juno awards, Canada's equivalent music honour.
Lightfoot achieved the height of his popularity in the 1970s, with songs from albums such as "Sundown," "Summertime Dream" and "Dream Street Rose" that built on his guitar-driven folk roots to produce more rock and pop-oriented songs.
He retained a loyal following in Canada and the United States through extensive concert touring.
Lightfoot's catalogue of compositions tops 200 songs, a number of them covered by such performers as Bob Dylan, Elvis Presley, Judy Collins, Barbra Streisand, Glen Campbell and Richie Havens. His "For Lovin' Me" and "Early Morning Rain" became hits for the folk trio Peter, Paul & Mary.
Lightfoot emerged from the folk music movement of the mid-1960s with signature tunes such as "Canadian Railroad Trilogy" and "Pussywillows, Cat-Tails."
In the 1970s, he picked up an electric guitar to pen pop ballads such as "Beautiful" and "I'm Not Supposed to Care."
Lightfoot's 1976 epic, "The Wreck of the Edmund Fitzgerald," about the drowning of 29 sailors when a freighter sank in a storm on Lake Superior, remains one of fans' most loved songs.
In it, Lightfoot coupled a soaring melody with poignant lyrics about the sailors' last hours.
He also topped the singles charts with such titles as the wistful 1974 song "Carefree Highway" and the ballad "If You Could Read My Mind," his first major international hit from 1971, about a dissolving marriage.
"If You Could Read My Mind" launched a successful run at Warner Bros Records, after Lightfoot defected from his previous label, United Artists.
He had been unhappy there in part over a lack of support he felt when many US radio stations banned his 1968 single "Black Day in July," about riots in Detroit the previous year, seeing it as too incendiary.
Two other major 1970s hits, "Sundown" and "Rainy Day People", were reportedly inspired by his volatile romance with backup singer and rock groupie Cathy Smith.
Smith died in 2020 after serving time in prison for injecting comic actor John Belushi with a fatal dose of heroin and cocaine in 1982.
Aside from writing lyrics and music, Lightfoot performed his songs in a warm tenor suited to ballads, though his voice grew thinner over the years, and he was known for his clear articulation as a vocalist.
He survived a major health crisis at age 63 in 2002, when he collapsed from severe stomach pain before a concert in his hometown of Orilla, Ontario, and had emergency surgery for abdominal bleeding caused by a ruptured aorta.
He endured weeks of hospitalisation and multiple operations before returning to the recording studio and live performances.
At the time of his illness, Canadian country singer and admirer Ian Tyson saluted Lightfoot as a national treasure.
"I don't think anybody before or since has, or will have, the impact on Canadian culture, through popular music or folk music, that Gordon Lightfoot had," Tyson told Reuters then.
Following news of his death, Prime Minister Justin Trudeau tweeted that Canada "has lost one of our greatest singer-songwriters".
"Gordon Lightfoot captured our country's spirit in his music and in doing so, he helped shape Canada's soundscape. May his music continue to inspire future generations, and may his legacy live on forever," Trudeau wrote.
