Ulis was born in Southfield, Michigan (a Detroit suburb), and lived in Lima, Ohio,[3] with his mother and younger brother, Ahron.

[3] He trained for basketball with his cousin and 2009 Big Ten Conference Defensive Player of the Year Travis Walton.

[3] Another of his cousins is Shareese Ulis, point guard for Cincinnati Lady Bearcats, who had been a two-time Toledo Blade Player of the Year.

[3] During his time in middle school, Ulis became friends with future Phoenix Suns teammate Devin Booker.

He reached 5 feet 8 inches (1.73 m) by late in his sophomore year and began being recruited by college basketball teams.

[12] Ulis finished fourth in the Illinois Mr. Basketball balloting behind Jabari Parker, Jahlil Okafor and Malcolm Hill.

[13] He was a first team All-state selection by the Chicago Tribune along with Parker, Okafor, Cliff Alexander and Jalen Brunson.

[20] Ulis entered his senior season as one of the five favorites to win Illinois Mr. Basketball (along with Okafor, Alexander, Brunson and Keita Bates-Diop).

[21] On December 7, 2013, at the UIC Pavilion in the Chicago Elite Classic, Ulis and Marion suffered one of their only two regular season losses to USC-bound guard Jordan McLaughlin and Etiwanda High School, which was ranked number 6 nationally by USA Today.

[26] Ulis posted a career-high 42 points on February 22 against Lake Forest High School to go along with 6 steals, 6 rebounds and 5 assists.

[28][29] On March 18, Marian lost its supersectional rematch against Edwardsville in overtime, again falling one game short of reaching the final four in Peoria, Illinois and finishing with a 28–3 record.

[34] He was named Associated Press Class 4A 1st team all-state with Alexander, Brunson, Okafor and Sean O'Mara.

Many thought Andrew would be Calipari's seventh consecutive point guard to declare for the NBA draft after his freshman season, but that Ulis would likely last much longer at Kentucky.

[41] Sources: During the offseason, Ulis wore a walking boot on his right foot following a pick-up game injury for precautionary reasons.

[52] Kentucky went undefeated in its first 38 games before losing to Wisconsin in the Final Four of the 2015 NCAA men's Division I basketball tournament.

[58][59] During the preseason, Mike Rutherford of SB Nation selected Ulis as one of its 10 most important college basketball players for 2015–16.

[66] In Kentucky's 2015–16 Southeastern Conference men's basketball season opener against the Ole Miss Rebels on January 2, Ulis posted 20 points and 10 assists.

[67][68] The game marked Ulis' first collegiate double-double and Kentucky's first 20-point and 10-assist performance since John Wall posted one on November 21, 2009.

[69] On January 5, Ulis posted his third straight 20-point performance with a career-high 23 points in a loss against the Ben Simmons-led LSU Tigers.

[70][71] On January 13, Ulis was among the 25 players included in the John R. Wooden Award Midseason Top 25 Watch List.

In a game between the two, Ulis posted new career highs with 27 points and 12 assists, leading the team to an 89–62 victory, after coach Calipari was ejected early.

[97] In the 2016 SEC men's basketball tournament, Ulis scored 25 points and had 4 assists in the semifinal victory over Georgia on March 12.

[100] In the 2016 NCAA men's Division I basketball tournament, Kentucky renewed its rivalry with Indiana in the round of 32 on March 19.

[119] He managed to record 13 points, 9 assists and 5 rebounds in a loss to the Santa Cruz Warriors before returning to Phoenix to play against the San Antonio Spurs the next day.

[123] On February 11, 2017, Ulis recorded a career-high 13 points and tied another career high with six assists in a 133–102 loss to the Houston Rockets.

[125] Following the break for the 2017 NBA All-Star Game, Ulis was moved into the main rotation of players ahead of Brandon Knight.

[131] Ulis received his first NBA start (in place of an injured, resting Eric Bledsoe) on March 15 against the Sacramento Kings and former Kentucky teammate Skal Labissière, who had a career-high 32 points.

[134] Two days later, Ulis, making his second career NBA start, scored 19 points and added eight assists in a 109–103 loss to Orlando Magic.

[147] After missing the first 8 games after the 2018 NBA All-Star Weekend, Ulis had extended playing time on March 10, 2018, when T. J. Warren, Booker and Josh Jackson were all sidelined, recording a double-double of 11 points and 10 assists in a 122–115 loss to the Charlotte Hornets.

[155] Ulis posted game highs of 25 points and 7 assists in Windy City's season-opening 96–71 victory against the Lakeland Magic on November 2.