Shiancoe was born in Birmingham, England to a Liberian mother and a Ghanaian father. As an infant, he emigrated to the United States with his mother, settling in Silver Spring, Maryland.
Shiancoe played high school football for Montgomery Blair High School in Silver Spring. He gained all-county honors competing at three positions: wide receiver, quarterback and tight end. He attended Morgan State University in Baltimore, Maryland where he transformed himself from a 190-pound freshman to a 250-pound senior tight end.
Shiancoe was drafted in the third round (91st overall) in the 2003 NFL Draft by the New York Giants. He played for the Giants for four seasons, mostly serving as a backup to Jeremy Shockey.
Shiancoe signed a five-year, $18.2 million contract with the Minnesota Vikings as a free agent in 2007. He compiled 208 receptions for 2,424 yards and 24 touchdowns in his five seasons as a Viking, in regular season games. He played in 80 games, of which he started in 66. He led NFC tight ends with seven touchdowns in 2008 and ranked third by a tight end in the NFL.
Shiancoe agreed to a one-year deal with the New England Patriots on July 24, 2012, reportedly worth $1.2 million. He was activated on November 11, 2012 after an injury of Aaron Hernandez and a suspension of Brandon Bolden. On December 11, 2012, he was released.
On July 28, 2013, Shiancoe signed a one-year deal to play for the Baltimore Ravens. The contract is considered a "qualifying contract" under which Shiancoe will stand to make the veteran minimum for a player with 10 or more years of service ($940,000) while counting only $555,000 against the Raven's salary cap. The signing was prompted by a season-ending hip injury suffered during training camp by Dennis Pitta. Less than a month on the team, Shiancoe was released after the third week of preseason on August 25, 2013.
On December 3, 2013, Shiancoe signed with the Tennessee Titans. On December 10, the Titans released Shiancoe.
Shiancoe was a contestant on NBC's Minute to Win It on September 8, 2010, playing to win money for the National Kidney Foundation. When he could not perform the card trick, where he had to blow off a deck of 53 playing cards with one joker at the bottom remaining on the bottle in a minute, he successfully performed the same trick on NFL Network again in less than 30 seconds, only to realize that the final Joker card was glued on.
Fox aired a post game segment following a victory over the Detroit Lions in 2008. Vikings owner Zygi Wilf was presenting the game ball to coach Brad Childress' son, Andrew, who had enlisted in the United States Marine Corps the day before. In the background, Shiancoe was shown unclothed for a moment before covering himself with a towel. According to the NFL and Fox Sports, the image lasted a fifth of a second. Fox Sports apologized for airing the image. Through his agent, Shiancoe said he was embarrassed by the unintentional incident.
Shiancoe currently resides in Prince George's County, Maryland. Although his first name has been commonly mispronounced as vi-SAWN-tee () or vi-SAWN-tae () he has clarified that the correct pronunciation is vi-SAWNTH ().
He plans to become involved in causes in his mother's home country of Liberia.