Tomlinson was born in Savanna-la-Mar, Jamaica and moved to Chicago, Illinois in March 2003. He attended Lane Technical College Prep High School in Chicago, where he was a two-sport star in both football and track. He was an All-state selection as a senior by both the Illinois High School Football Coaches Association and Chicago Tribune. He was named the team MVP as a senior. He was a two-time All-city selection. He was also a four-time first team All-conference selection. He helped lead his high school team to the 2008 Chicago Public League football championship.
In addition, Tomlinson lettered in track & field at Lane. At the 2009 Chicago Public League T&F Championship, he placed first in the discus (140-06 or 42.9m) and second in the shot put. In the 2009 Illinois 3A State T&F Championship meet, he threw personal-bests of 43.01 meters (141-1) in the discus throw and 14.58 meters (47-7) in the shot put to place 17th and 22nd, respectively, in the preliminary heats.
On August 31, 2017, Tomlinson was traded to the San Francisco 49ers for a 2019 fifth-round draft pick. After missing the season opener, Tomlinson started the next 15 games at left guard in 2017.
On May 2, 2018, the 49ers declined the fifth-year option on Tomlinson's contract, making him a free agent in 2019. However on June 22, 2018, Tomlinson signed a three-year, $18 million extension with the 49ers with $10 million guaranteed.