[3] Donohue and Hubbell were romantically involved in the early years of their partnership, but ultimately they opted to focus on their competitive career.

Making their international debut, they won gold at the 2008–09 ISU Junior Grand Prix event in Ostrava, Czech Republic.

Their results qualified them for the 2008–09 Junior Grand Prix Final in South Korea, but they withdrew before the competition due to an injury to Gilles.

They trained in Canton, Michigan, under the coaching team of Igor Shpilband and Marina Zueva, and competed in the senior ranks.

[8] The two decided to train at the Detroit Skating Club under the guidance of the coaching team of Pasquale Camerlengo, Anjelika Krylova, and Natalia Annenko-Deller.

Hubbell/Donohue were first alternates for the 2014 World Championships but did not take the slot made available when Meryl Davis / Charlie White withdrew; Hubbell had sustained a torn labrum in her left hip[14] and underwent surgery in March 2014.

[15] In November 2015, Hubbell/Donohue won their first Grand Prix title, taking gold at the 2015 Trophée Éric Bompard in Bordeaux as a result of their first place in the short dance, ahead of Canada's Piper Gilles / Paul Poirier.

In March, Hubbell/Donohue won a small bronze medal for their short dance at the 2017 World Championships in Helsinki, Finland.

After taking bronze at the 2017 Skate Canada International and silver at the 2017 NHK Trophy, they qualified to their third consecutive Grand Prix Final.

In the short dance, they placed third, behind training mates Tessa Virtue / Scott Moir and Gabriella Papadakis / Guillaume Cizeron, and 0.02 points ahead of the Shibutanis.

In the free dance, Donohue put both hands down in the middle of a sliding move, which constituted a technical fall.

[21] In the free dance, they unexpectedly dropped to fourth place following multiple errors, including receiving only a base level on their stationary lift after it was deemed non-stationary.

Donohue was suffering from bronchitis at the time of the event and commented that he hoped to have "two working lungs" by their next competition the following week.

[30] Third in the free dance after having revised nine of the program elements in the interim since Skate Canada International, they won the bronze medal overall.

[31] Entering the 2020 U.S. Championships seeking to win a third consecutive title, they placed second in the rhythm dance, with Donohue slightly losing balance at one point in the Finnstep pattern and their lift being graded at only a level 3.

[33] Returning to the Four Continents Championships after the disappointment of the previous year, Hubbell/Donohue won the rhythm dance again, albeit by a margin of only 0.03 over Chock/Bates, and 2.03 points ahead of Gilles/Poirier in third.

[36] Hubbell and Donohue recruited former training partner and double-Olympic champion Scott Moir as one of their choreographers for the new season, planning to regain momentum lost in the previous year, which they attributed in part to losing confidence in their programs after their loss at Skate Canada.

Donohue remarked afterward on his "overwhelming gratitude, being our last Skate America and four consecutive wins for us, it means quite a lot, especially to be able to have a live audience" following the pandemic restrictions in the preceding year and a half.

[47][49] They were initially assigned to the 2021 Cup of China as their second Grand Prix, but following its cancellation, they were reassigned to the 2021 Gran Premio d'Italia.

[50] With training partners Papadakis/Cizeron also assigned to the event, Hubbell/Donohue were the presumptive silver medalists, and finished second in both segments of the competition despite a late-program flub on their free dance choreographic lift.

Hubbell joked afterward, "we made a mistake at the end, but sometimes you jump in the air, and you hit your partner in the crotch.

"[51] Their results qualified them to the Grand Prix Final, but it was subsequently canceled due to restrictions prompted by the Omicron variant.

[52] Seeking to defend their title at the 2022 U.S. Championships, Hubbell/Donohue placed second in the rhythm dance due to errors, ending up 2.55 points behind Chock/Bates.

They scored a new personal best of 86.56 to win the segment, securing ten points for the American team and notably prevailing over reigning World champions Sinitsina/Katsalapov of the ROC.

[57] Following a positive doping test of Russia's gold medalist Kamila Valieva, the team members were not awarded their medals, pending an investigation.

With Papadakis/Cizeron taking the gold medal and Chock/Bates the bronze, the entire podium consisted of skaters from the Ice Academy of Montreal.

[65][66] Burlesque A Star Is Born: Romeo and Juliet "Love" medley: Note: The 2015 Trophée Éric Bompard was cancelled after the November 2015 Paris attacks.