Douglass played at Carmel High School before going to the University of Michigan where he was a co-captain with Zack Novak in his junior and senior season. Douglass played in 136 consecutive games while at Michigan, setting the record for the most games played by a Michigan basketball player. During his career at Michigan, Douglass averaged 28.7 minutes per game and 6.9 points per game while shooting 38% from the field and 34% from three-point range. During his senior season for the 2011–12 Michigan Wolverines, the team earned a share of the 2011–12 Big Ten Conference season regular season championship.
On June 29, 2012, Douglass started his professional career with the Spanish team Basket Navarra Club of the LEB Oro. On February 8, 2013, Douglass recorded a career-high 22 points, shooting 7-of-10 from the field, along with three rebounds in a 71–67 win over Cáceres Ciudad del Baloncesto.
On June 12, 2013, Douglass signed a two-year deal with Israeli team Hapoel Gilboa Galil. On November 24, 2013, Douglass recorded a season-high 18 points, shooting 8-of-13 from the field, along with six assists and two steals in a 63–73 loss to Barak Netanya. Douglass helped Gilboa Galil reach the 2014 Israeli League Quarterfinals, as well as reaching the 2014 Balkan League Finals, where they eventually lost to Levski Sofia.
On September 22, 2014, Douglass signed with Hapoel Afula of the Liga Leumit. In 29 games played for Afula, he averaged 14.3 points, 2.9 rebounds and 3.3 assists, shooting 38 percent from 3-point range.
On July 6, 2015, Douglass signed a one-year deal with Maccabi Kiryat Gat. In 33 games played during the 2015–16 season, he averaged 7.5 points, 1.9 rebounds and 1.4 assists, shooting 39 percent from 3-point range.
On June 25, 2016, Douglass signed with Ironi Nahariya for the 2016–17 season. On May 11, 2017, Douglass recorded a season-high 17 points, shooting 5-of-8 from three-point range, along with 3 assists and two steals in an 87–99 loss to Bnei Herzliya. Douglass helped Nahariya reach the 2017 FIBA Europe Cup Quarterfinals, as well as reaching the 2017 Israeli League Quarterfinals, where they eventually lost to Hapoel Jerusalem 2–3 in a playoff series. On July 25, 2017, Douglass signed a one-year contract extension with Nahariya.
On August 2, 2018, Douglass signed with Hapoel Tel Aviv for the 2018–19 season. On May 27, 2019, Douglass recorded a season-high 16 points, shooting 4-of-5 from three-point range in a 72–85 playoff loss to Maccabi Tel Aviv.
Maccabi Ashdod (2019–present)
On July 27, 2019, Douglass signed a one-year deal with Maccabi Ashdod.