Senior Season — 2012-13O'Neil became the Big Red's first three-time All-Ivy League selection since 2002, when she was placed on the Second Team for singles. She once again anchored the top spot in singles for the Big Red, going 9-6 in dual matches and matching the 2-5 mark she posted as a junior in Ivy play. She was 7-1 in nonleague matches, including wins over once-ranked Kim Berghaus, of Maryland-Baltimore County, and Anna Rapoport, of Fairleigh Dickinson. In league play, O'Neil defeated Dartmouth's Sarah Leonard in straight sets and Brown's Misia Krasowski in a third set. She bounced around the doubles order, winning eight of her 14 matches in dual play. That included a 6-3 record when competing with sophomore Lauren Frazier at the No. 1 position, though O'Neil also teamed with freshmen Christy Kung and Laila Judeh, and sophomore Nina Turudic from the No. 3 spot. ... O'Neil was also 9-3 in singles and 8-6 in doubles during tournament play. She won the 'A' singles bracket at both the Cornell Fall Invitational and Cornell Winter Invitational at Reis Tennis Center. ... O'Neil served as a co-captain alongside classmate Christine Ordway.
Junior Season — 2011-12O'Neil had a breakthrough season, earning an All-Ivy League Second Team selection in singles and an All-Ivy League First Team selection alongside Lauren Frazier in doubles. O'Neil was used exclusively at the No. 1 singles spot for the Big Red, posting an 8-10 record in the spring with a 2-5 mark in Ivy League matches. She was 8-5 in fall tournament play. O'Neil excelled in some of her toughest matches of the season, posting a 3-0 record in matches against ranked opponents. She defeated UMBC's Kim Berghaus, ranked No. 111 at the time of their Feb. 4 match, then twice knocked off Princeton's Hilary Bartlett. O'Neil shot up to the top spot in the lineup after competing primarily at Nos. 5 and 6 singles as a sophomore. At the team's postseason banquet, O'Neil was named both the Most Valuable Player and Most Improved Player. In doubles, O'Neil and Frazier ended the season ranked 73rd in the nation, posting a 8-3 record in dual matches and 5-2 in Ivy play while competing exclusively at the No. 1 position. The success culminated with a sweep of ranked pairs April 27-29 — 48th-ranked Sol Eskenazi and Jules Rodin from Penn and 40th-ranked Hilary Bartlett and Lindsay Graff from Princeton.
Sophomore Season — 2010-11O’Neil had a solid sophomore season, posting a 12-11 record overall and a mark of 9-7 in the spring. She also finished with a record of 3-4 in the Ivy League. In doubles, O’Neil finished with a 4-6 record overall, going 2-1 in the spring.
Freshman Season — 2009-10Playing mostly at the No. 3 and No. 4 spots during her rookie season, O’Neil finished the year with an 8-10 record overall and a mark of 1-4 in Ivy League play. In the No. 2 doubles spot, O’Neil went 11-7 overall and 2-3 in the conference.
At Lynnfield High School O’Neil achieved the highest recruiting ranking nationally with a 55. She lettered three times and was a Massachusetts State Individual Champion. O’Neil was also the Cape Ann League Player of the Year and was a league all-star for two years.
PersonalSarah Jean O’Neil is the daughter of Richard and Elizabeth O’Neil and she has an older sister and a younger brother. Her mother was a gymnast for the University of Michigan. O’Neil is enrolled in the College of Agriculture and Life Sciences.