Stanford Cardinal, 2014–2017

During her freshman season in 2014, Sullivan started in 23 of the 24 matches in which she played. She scored her first goal for the Cardinal during a match against University of Dayton and served four assists throughout the season ranking third on the team. She made the All-Freshman First Team for Top Drawer Soccer, as well as the Pac-12 First Team and NSCAA All-Pacific Region Second Team. She was also awarded Pac-12 Freshman of the Year and named National Freshman of the Year by Top Drawer Soccer and Soccer America.

As a sophomore, Sullivan played and started in all 23 games. She scored 5 goals, including three game-winners, and provided 2 assists. As a junior, Sullivan led Stanford in points (29), goals (11) and game-winning goals (4). She was named the Pac-12 Player of the Year and earned All-Pac-12 first team honors for the third consecutive season.

As a senior, Sullivan tallied three goals and six assists and led Stanford to their second national championship, scoring in the College Cup final. She won the Hermann Trophy, after being a finalist in 2016 and a semifinalist in 2015.^[3]

Washington Spirit Reserves, 2012–2015

Sullivan played in the USL W-League during the 2012–2015 seasons.^[6][7] She played with D.C. United Women in 2012,^[8] which was later renamed the Washington Spirit Reserves for the 2013–2015 seasons.

Washington Spirit, 2018–present

On January 18, 2018, Sullivan was selected as the number one overall draft pick at the 2018 NWSL College Draft by the Washington Spirit.^[9] Sullivan appeared in every game for the Spirit, except for the last game of the season which she missed as she was completing in the Nordic Cup with U.S. U-23.

Sullivan was named a finalist for 2018 NWSL Rookie of the Year, she finished second in voting for the award behind winner, Imani Dorsey.^[10]

She returned to Washington for the 2019 NWSL season and was named team captain.^[11]

Youth national teams

Sullivan has represented the United States on the senior national team as well as the under-15, under-17, under-20, and under-23 national teams.^[3] Sullivan competed for the United States at the 2012 CONCACAF Women's U-17 Championship in Guatemala where she helped the under-17 national team win gold.^[12] Despite being the youngest player on the under-20 national team roster at the 2014 CONCACAF Women's U-20 Championship, she co-captained the team to a 2014 FIFA U-20 Women's World Cup berth.^[12]

On August 23, 2018, she was named to the United States U-23 team for the 2018 Nordic tournament.^[13]

Senior National Team

She earned her first cap with the senior national team during an international friendly match against Switzerland on October 19, 2016, and earned Player of the Match for her impressive performance.^[14] She earned her first assist a few days later on October 23, 2016.^[15] She then played in two more matches on November 10 and 13 where she earned another assist.^[16] However, she tore her ACL a few days later during a college match on November 18, 2016.^[17] She missed a large part of the year due to the injury but made her return to the national team on October 19, 2017.^[18]

Sullivan was named to the 23-player roster for the 2018 SheBelieves Cup, the U.S. won the tournament for the second time.^[19] She was on the 35-player provisional roster for the 2018 CONCACAF Women's Championship but was not named to the final 20-player roster.^[20]

In 2019, Sullivan was originally not included on the January camp roster but was added to the roster by head coach Jill Ellis.^[21] Sullivan was also named to the team for the 2019 SheBelieves Cup.^[22]

International

As of match played October 26, 2023

International goals

Key (expand for notes on "international goals" and sorting)
Location	Geographic location of the venue where the competition occurred Sorted by country name first, then by city name
Lineup	Start – played entire match on minute (off player) – substituted on at the minute indicated, and player was substituted off at the same time off minute (on player) – substituted off at the minute indicated, and player was substituted on at the same time (c) – captain Sorted by minutes played
Goal in match	Goal of total goals by the player in the match Sorted by total goals followed by goal number
#	NumberOfGoals.goalNumber scored by the player in the match (alternate notation to Goal in match)
Min	The minute in the match the goal was scored. For list that include caps, blank indicates played in the match but did not score a goal.
Assist/pass	The ball was passed by the player, which assisted in scoring the goal. This column depends on the availability and source of this information.
penalty or pk	Goal scored on penalty-kick which was awarded due to foul by opponent. (Goals scored in penalty-shoot-out, at the end of a tied match after extra-time, are not included.)
Score	The match score after the goal was scored. Sorted by goal difference, then by goal scored by the player's team
Result	The final score. Sorted by goal difference in the match, then by goal difference in penalty-shoot-out if it is taken, followed by goal scored by the player's team in the match, then by goal scored in the penalty-shoot-out. For matches with identical final scores, match ending in extra-time without penalty-shoot-out is a tougher match, therefore precede matches that ended in regulation
aet	The score at the end of extra-time; the match was tied at the end of 90' regulation
pso	Penalty-shoot-out score shown in parentheses; the match was tied at the end of extra-time
	Light-purple background color – exhibition or closed door international friendly match
	Light-yellow background color – match at an invitational tournament
	Light-orange background color – Olympic women's football qualification match
	Light-blue background color – FIFA women's world cup qualification match
	Pink background color – Continental Games or regional tournament
	Orange background color – Olympic women's football tournament
	Blue background color – FIFA women's world cup final tournament
NOTE on background colors: Continental Games or regional tournament are sometimes also qualifier for World Cup or Olympics; information depends on the source such as the player's federation. NOTE: some keys may not apply for a particular football player

Goal	Date	Location	Opponent	Cap	Lineup	Min	Assist/pass	Score	Result	Competition
1	2021-09-16[m 1]	Cleveland, Ohio, U.S.	Paraguay	18	Start	25	Lynn Williams	5350.03005 3–0	5950.09005 9–0	Friendly
2						49	Mallory Pugh	5750.07005 7–0
3	2022-04-09[m 2]	Columbus, Ohio, U.S.	Uzbekistan	26	Start	26	Alana Cook	5150.01005 1–0	5950.09005 9–1

Match reports