For high school, Ulis moved toMatteson, Illinois,[3] where he lived with his father, James.[6] In Ohio, he had been used to winning a high percentage of his games.[6] When he arrived at Marian Catholic, he started his first game as a freshman against futureIllinois Fighting Illini men's basketball starting guardTracy Abrams.[3] He did not initially enjoy team success. As a freshman, he was 5 feet 3 inches (1.60 m) tall and was being recruited by opposing high schools. He reached 5 feet 8 inches (1.73 m) by late in his sophomore year and began being recruited by college basketball teams.[6] By the beginning of his junior season, Marian Catholic was regarded as a serious contender thanks to Ulis.[7]
"[Kentucky made the list because] of the success they have had there recently...John Calipari has produced the most point guards in recent years and has taken them right to the NBA. He obviously knows how to coach point guards. He knows how to put them in positions to lead the team. He’s a tough coach. There’s accountability from Day 1 to win and win at a high level."
By August 8, 2013, when he was ranked as the 38th-best prospect in the national class of 2014 and its eighth-best point guard byESPN, he had several offers and named Iowa, Kentucky (although he did not have an offer from them at the time),Michigan State andUSC as his finalists (eliminating DePaul,Florida State,Northwestern andPurdue).[16] Walton, Tyler's cousin, had played for Michigan State.[16] He received an official offer from Kentucky on August 16.[15] In early September, Ulis announced that he would not take an official visit to USC and had eliminated them from consideration.[17] On September 13, Ulis committed to Kentucky.[18][19] Subsequently,Tyus Jones canceled his September 27–29 official visit to Kentucky.[20]
Ulis entered his senior season as one of the five favorites to win Illinois Mr. Basketball (along with Okafor, Alexander, Brunson andKeita Bates-Diop).[21] On December 7, 2013, at theUIC Pavilion in the Chicago Elite Classic, Ulis and Marion suffered one of their only two regular season losses to USC-bound guardJordan McLaughlin andEtiwanda High School, which was ranked number 6 nationally byUSA Today. Ulis had 30points, 7assists and 5rebounds.[22][23] The January 25, 2014, matchup against junior Brunson andStevenson High School was widely anticipated in the local press as the matchup of the two best point guards in the state.[24][25] Stevenson won as Brunson had 32 points on 9-for-15field goal shooting and an 11-for-14free throw performance. Ulis had 23 points and 9 assists, including 18 points and 3 assists in the final eight minutes, but was only 5-for-20 from the field for the game.[26] Ulis posted a career-high 42 points on February 22 againstLake Forest High School to go along with 6steals, 6 rebounds and 5 assists.[27]
During his senior year, Marian was the number 1 seed in theThornton sectional of the IHSA Class 4A tournament. On March 11, Ulis had 40 points to lead Marian pastBloom High School 66–45. In the game, which was a rematch from the prior year, he made his first six shots, all three-pointers.[28][29] On March 18, Marian lost its supersectional rematch against Edwardsville inovertime, again falling one game short of reaching the final four inPeoria, Illinois and finishing with a 28–3 record. In the game, Ulis, who had 23 points and 4 assists, tied the score with 21 seconds in regulation and with 50 seconds left in overtime.[30][31] In the April 18 Jordan Brand Classic, Ulis posted 9 points and 9 assists.[32]
He was selected to the 2014 McDonald's All-American Game on January 29 (along with fellow Chicagoans Okafor and Alexander as well as along with fellow Kentucky commitsKarl-Anthony Towns,Trey Lyles andDevin Booker).[2][33] On March 10 he was one of 26 players selected for the April 18, 2014 Jordan Brand Classic again along with fellow Chicagoans Okafor and Alexander as well as along with fellow Kentucky commits Towns, Lyles and Booker.[34] He was namedAssociated Press Class 4A 1st team all-state with Alexander, Brunson, Okafor and Sean O'Mara.[35] Ulis finished third to Okafor and Alexander in theIllinois Mr. Basketball voting.[36] He was the runner-up in both the skills competition and the three-point contest at the McDonald's All-American Game.[37] He was a 2014USA Today third-teamAll-USA Boys Basketball Team selection.[38]
The decision byAndrew Harrison andAaron Harrison on whether to enter the2014 NBA draft would be the determining factor on whether Ulis became an immediate starter or not. Many thought Andrew would be Calipari's seventh consecutive point guard to declare for theNBA draft after his freshman season, but that Ulis would likely last much longer at Kentucky.[39][40] On April 25, the Harrisons announced that they would be returning to Kentucky.[41]
During the offseason, Ulis wore awalking boot on his right foot following a pick-up game injury for precautionary reasons.[42] Ulis was also named to the 36-man 2014–15Bob Cousy Award preseason watchlist and theWayman Tisdale Award watchlist.[43][44] Ulis quickly earned a reputation as a difference maker whose contributions may not be obvious in the statistics.[45] On December 10, he was sidelined with an injury.[46] Ulis posted a season-high 14 points on December 27 againstLouisville in theKentucky–Louisville rivalry game known as the Battle For The Bluegrass, earning the MVP of the game from the Bluegrass Sports Commission.[47][48] On December 29, his effort was recognized with an SEC Freshman of the Week honor.[49][50] Ulis did not start in any his 37 games played as a freshman, but averaged 23.8 minutes played.[51] Following the season, he was named to the 8-man 2015 SEC All-Freshman Team.[52] Kentucky went undefeated in its first 38 games before losing toWisconsin in the Final Four of the2015 NCAA men's Division I basketball tournament.[53] Ulis led the team in assists per game.[54]
Ulis opened the season in the starting lineup against theAlbany Great Danes on November 13.[64] On November 17, Ulis posted game-high and career-high 18 points as well as game-high 6 assists with no turnovers in 40 minutes of play in a victory over the defending national championDuke Blue Devils in theChampions Classic.[65][66] He posted a game-high and career-high 21 points as well as a game-high 5 assists on November 21 againstWright State.[51][66] As a result, on November 23, he earned SEC Co-Player of the Week (along withKenny Gaines).[66] In Kentucky's2015–16 Southeastern Conference men's basketball season opener against theOle Miss Rebels on January 2, Ulis posted 20 points and 10 assists.[67][68] The game marked Ulis' first collegiatedouble-double and Kentucky's first 20-point and 10-assist performance sinceJohn 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 theBen Simmons-ledLSU Tigers.[70][71] On January 13, Ulis was among the 25 players included in theJohn R. Wooden Award Midseason Top 25 Watch List.[72] On January 21, Ulis went 14–15 from the free throw line and 2–3 on three-point shots to post 24 againstArkansas.[73] Ulis was named to the January 25, 20-man Oscar Robertson Trophy midseason watch list.[74] On January 30, Ulis posted a career-high 26 points and 8 assists against #4-rankedKansas, but Kentucky lost in overtime.[75] On February 1, Ulis was named one of 10 finalists for the Bob Cousy Point Guard of the Year Award.[76] Entering play on February 13, Kentucky andSouth Carolina were tied atop of the2015–16 Southeastern Conference standings. 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.[77] He was named to the 35-man midseason watchlist for theNaismith Trophy on February 11.[78] Ulis was included in the Wooden Award Late season Top 20 Watch List on February 12.[79] On February 15, Ulis earned SEC Player of the Week honors again.[80] On February 29, Ulis was among the 11 finalists for the Robertson Trophy.[81] On March 5, Ulis closed out the regular season with a career-high 14 assists and 14 points against the LSU Tigers.[82]
At the conclusion of his sophomore season, Ulis announced his intention to forgo his final two seasons of eligibility and enter the2016 NBA draft. During the 2016NBA Draft Combine, Ulis was not only the second-shortest player to participate in the event (behind onlyKay Felder, who measured at 5'9½" with shoes on (5'8½" without shoes) as opposed to an even 5'10" with shoes on (5'8¾" without them)), but he was also the lightest-recorded player in draft combine history at 149 pounds (68 kg), which affected his draft stock.[102] Furthermore, about two weeks before the draft began, it was revealed that Ulis had a problem with his hip that may one day require surgery. As a result, his draft stock declined from being an expected mid-first-round selection to being either a projected late-first-round or early-second-round selection.[103] Ulis downplayed the issue, claiming that his hip was just fine.[104] However, Ulis was selected by thePhoenix Suns in the second round with the 34th selection,[105] being reunited with his best friend and former college teammateDevin Booker in the process.[106] On July 7, he signed with the Suns and joined the team for the2016 NBA Summer League.[107] Ulis received the equivalent of a late first-round pick's contract, starting at around $1 million and having the same two guaranteed years with two team option years.[108] In the Summer League, his play compared favorably to the four point guards who were taken in the first round.[109] Over six games at the Las Vegas Summer League, he averaged 14.5 points and 6.3 assists per game,[110] subsequently earning All-NBA Summer League Second Team honors.[111]
Ulis debuted with the Suns on October 26, 2016, against theSacramento Kings.[112] He posted 2 points, a rebound, an assist, a steal and a block in 13 minutes of action during the blowout loss,[113] but was on the court as Phoenix cut the deficit from 26 to 10 points at one point.[114] His play in mop-up time earned him a role in the second unit.[115] On October 31, Ulis posted a team-high 6 assists in 18 minutes of play against theLos Angeles Clippers.[116] On November 18, he scored a season-high 10 points and 4 steals in a 116–96 win over theIndiana Pacers.[117] He matched the 4 steals and added 4 rebounds the next night against thePhiladelphia 76ers.[118] On December 14, he was assigned to theNorthern Arizona Suns of theNBA Development League.[119] He managed to record 13 points, 9 assists and 5 rebounds in a loss to theSanta Cruz Warriors before returning to Phoenix to play against theSan Antonio Spurs the next day.[120]
On December 29, he matched his season and career high with 10 points in 15 minutes in a 99–91 win over theToronto Raptors.[121] On February 8, there was an oncourt altercation between the Suns and theMemphis Grizzlies resulting in suspensions and fines, including a $15,000 fine for Ulis[122] (who came to the defense of Booker).[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 theHouston Rockets.[124] On February 17, he had his number retired at Marian Catholic.[125]
Following the break for the2017 NBA All-Star Game, Ulis was moved into the main rotation of players ahead ofBrandon Knight.[126] In his new role, Ulis set new career highs in assists on February 28 againstMemphis (7),[127] and March 2 againstCharlotte (8);[128] and new career highs in points on March 3 againstOklahoma City (14)[129] and March 5 againstBoston (20, including abuzzer-beating, game-winning three-point shot).[130] Ulis helped improve the team's assist production post All-Star break from 18.6 assists per game (tied for last in the NBA) prior to the break to 24.8 per game in the first two weeks after the break.[131] Ulis received his first NBA start (in place of an injured, restingEric Bledsoe) on March 15 against theSacramento Kings and former Kentucky teammateSkal Labissière, who had a career-high 32 points. Ulis record his first career double-double with 13 points and a season-high 13 assists in a 107–101 loss against the Kings.[132][133] Ulis became the first Suns rookie with at least 12 points and 12 assists in a game sinceSteve Nash in November 1996.[134] Two days later, Ulis, making his second career NBA start, scored 19 points and added eight assists in a 109–103 loss toOrlando Magic.[135] On March 30, he had 16 points and matched his career best with 13 assists in a 124–118 loss to the Clippers.[136][137]
On April 2, he had a near-triple-double with career highs of 34 points and nine rebounds as well as nine assists in a 123–116 loss to theHouston Rockets.[138][139] The 34 points was a 2016–17 season single-game high for all NBA rookies.[139]
Ulis was subsequently named Western Conference Rookie of the Month for April,[139] becoming the second Suns rookie to win the award during the 2016–17 season (afterMarquese Chriss in January). It was the first time two different Suns earned the award in the same season since the1987–88 NBA season.[140] Ulis ended April by leading all rookies in points (20.7) and assists (6.8), while also recording 3.8 rebounds. His average of 20.7 points and 6.8 assists was the most by an NBA rookie in a month sinceDamian Lillard in March 2013.[140] While he averaged 7.3 points, 3.7 assists and 1.6 rebounds in 61 games for the season, he averaged 16.1 points and 8.5 assists in games that he started.[140] Ulis finished 14th in the voting for the 10-manNBA All-Rookie team.[141]
On May 10, 2017, Ulis had surgery performed on his right ankle by Dr. Martin O'Malley at the Hospital for Special Surgery in New York City.[142] He subsequently missed the2017 NBA Summer League,[143] but returned in time for the start of training camp. Ulis made his first start of the season on November 11, 2017, in a 118–110 win over theMinnesota Timberwolves.[144] Six days later, in their 122–113 win over theLos Angeles Lakers, Ulis was involved in a late-game shoving match with Lakers guardKentavious Caldwell-Pope.[145] Ulis recorded his first double-double of the season with 12 points and a season-high 12 assists in a 115–101 win over thePhiladelphia 76ers on December 4.[146] Ulis posted a career-high[citation needed] 5 steals on January 29 against theMemphis Grizzlies.[147]
On June 30, 2018, Ulis was waived by the Suns.[152] He later signed with theGolden State Warriors on September 24, 2018,[153] before being waived on October 12.[154]
On October 15, 2018, Ulis was claimed off waivers by theChicago Bulls, joining the team on atwo-way contract with theWindy City Bulls of theNBA G League.[155] Ulis posted game highs of 25 points and 7 assists in Windy City's season-opening 96–71 victory against theLakeland Magic on November 2.[156] On December 21, 2018, Ulis was reported to have undergone a left hip arthroscopy.[157] On December 27, 2018, Ulis was waived by the Bulls.[158]
On September 24, 2019, Ulis signed with theSacramento Kings.[159] On October 20, Ulis was waived by the Kings.[160] He ultimately landed with Sacramento's G League affiliate, theStockton Kings.[161] Ulis averaged 6.8 points and 3.8 assists per game with Stockton.[162]
In October 2021, Ulis joined theSanta Cruz Warriors.[163] However, he was waived on November 4, before appearing in a single game.[164]
While recuperating from a February 2022 car accident, he re-enrolled as a full-time student at Kentucky to work towards his degree during the 2022–23 academic year, making him eligible to be hired as a student assistant coach forthe team. In late December, he joined the team in that role.[165]