Davies was born in Philadelphia, but adopted by single mother Kathy Davies and raised in Provo, Utah. He attended Provo High School, where his team won state titles in his sophomore and junior seasons. After considering schools such as California, Gonzaga, and Utah, Davies chose to play college basketball at Brigham Young. After playing a reserve role as a freshman in 2009–10, Davies became a key player for the Cougars as a sophomore. He served as the key inside player for the small, sharp-shooting 2010–11 Cougars. BYU raced to a 27–2 record and was ranked no. 3 in the AP Poll when Davies was suspended from the team for violating BYU's honor code by having premarital sex with his girlfriend. Davies was reinstated to the team as a junior and was named to the All-West Coast Conference team in each of his last two seasons at BYU. As a senior, Davies served as team captain and averaged 17.7 points and 8.0 rebounds per game.
Professional career
Following his graduation from BYU, Davies was invited to participate in the Portsmouth Invitational Tournament pre-NBA draft camp. Davies performed well, averaging 20.7 points per game on 68% shooting and grabbing 9.3 rebounds per game. He was named MVP of the PIT. Davies' performance earned him an invitation to the Chicago NBA Draft combine. After going undrafted in the 2013 NBA draft, he joined the Los Angeles Clippers for the 2013 NBA Summer League. On September 5, 2013, he signed with the Clippers, but was later waived on October 21.
On October 28, 2013, Davies signed with the Philadelphia 76ers. He played in his first NBA game on November 2, 2013 against the Chicago Bulls, scoring two points in two minutes of action. On January 18, 2014, he fractured his right small finger, requiring surgery and up to a month of rehabilitation. On November, 5, 2014, Davies scored a career-high 20 points in an 89-91 loss to the Orlando Magic.
On December 11, 2014, Davies was traded to the Brooklyn Nets in exchange for Andrei Kirilenko, Jorge Gutiérrez, the Nets' second-round draft pick in 2020, the right to swap second-round picks in 2018, and cash considerations. On January 6, 2015, he was waived by the Nets after appearing in seven games.
In the summer of 2017, Davies played in The Basketball Tournament on ESPN for Team Fredette. He competed for the $2 million prize, and for Team Fredette, he scored 20 points and grabbed seven rebounds in their first round game, which they lost to Team Utah 100-97. On June 23, 2017, Davies signed with a 1+1 contract with Lithuanian team Žalgiris Kaunas of the Lithuanian Basketball League. Over his two seasons with Žalgiris, Davies helped the team achieve much success, in particular in the EuroLeague. On May 9, 2019, Davies was named to the All-EuroLeague First Team, becoming the first Žalgiris player to win the award in 15 years since Arvydas Sabonis in 2004.
On July 4, 2019, Davies signed a two-year deal with the Spanish club Barcelona. In his second game with Barcelona, Davies recorded 24 points and 11 rebounds in a 95-87 win over Saski Baskonia.
