After spending his first seven seasons with the Dallas Mavericks, he was traded to the Brooklyn Nets in February 2023, and then to the Lakers in late December 2024.

[1] In September 2010, Finney-Smith committed to Virginia Tech,[2] and later signed a National Letter of Intent with the Hokies in December.

He led the team to back-to-back Group AAA state championships, along with Eastern Region and District titles.

He finished his high school career as a two-time VHSL Class AAA Player of the Year and first-team all-state, all-region, All-Tidewater and all-district.

[4] As a sophomore in 2013–14, Finney-Smith was named SEC Sixth Man of the Year, becoming just the second Gator to win the award after Chris Richard in 2007.

He also recorded the first 20/15 performance by a Gator in a road game during Billy Donovan's tenure, totaling a personal-best 22 points in an overtime win over Arkansas.

[1] As a junior in 2014–15, Finney-Smith was named second-team All-SEC by the coaches and was Florida's leading scorer (13.1), rebounder (6.2) and three-point shooter (.426).

[13] On November 2, 2018, Finney-Smith scored a season-high 19 points, alongside seven rebounds, two assists and two steals, in a 118–106 loss to the New York Knicks.

Finney-Smith made his playoff debut on August 17, recording nine points, four rebounds, two assists and two steals in a 118–110 Game 1 loss.

On May 8, during the Mavericks' second-round series against the Suns, Finney-Smith scored a playoff career-high 24 points, alongside eight three-pointers and eight rebounds, in a 111–101 Game 4 win.

[28] On December 29, 2024, Finney-Smith was traded from the Nets alongside Shake Milton to the Los Angeles Lakers in exchange for Maxwell Lewis, D'Angelo Russell and three future second-round picks.