An Atlantic salmon (Salmo salar) mixed-stock fishery generally operating from August through October exists off the coast of Greenland and primarily harvests 1 sea-winter (1SW) North American and European origin salmon destined to return to natal waters as 2 sea-winter (2SW) spawning adults. To collect data on the biological characteristics and origin of the harvest necessary for international stock assessment efforts, parties to the North Atlantic Salmon Conservation Organization’s (NASCO) West Greenland Commission (WGC) agreed to participate in an international sampling program for the 2020 and 2021 fisheries. Due to the ongoing restrictions and uncertainty related to the COVID-19 pandemic, the 2020 traditional sampling program involving international collaborators traveling to Greenland and sampling the harvest was canceled. As an alternative, a contingency plan was developed which involved providing sampling kits to Greenland’s Fisheries License Control Authority (GFLK) Wildlife Officers, staff at the Greenland Institute of Nature Resources (GINR), and individual fishers throughout Greenland in an attempt to develop a Citizen Science sampling effort. In 2021, the traditional sampling program was again implemented, and international collaborators traveled to Greenland and sampled the harvest. Sampling kits were also provided to staff at the GINR, and the Citizen Science was modified and pursued. Reported landings were 31.7 metric tons (t) in 2020 and 41.0 t in 2021. In 2020, only 197 samples were collected whereas 1,548 were collected in 2021. The collected samples represented approximately 1% and 17% of the reported landings in 2020 and 2021, respectively. Delays in collating the 2020 samples resulted in the samples not being shipped to the North American collaborators in time for sample processing and summation prior to the 2021 International Council for the Exploration of the Sea (ICES) Working Group on North Atlantic Salmon (WGNAS) meeting. Delays also occurred in 2021, resulting in only a portion of the samples being available for processing prior to the 2022 WGNAS meeting. All samples have since been processed. In 2020, the mean length of sampled fish was 67.1 cm, and the mean whole weight was 3.50 kg. North American origin fish were primarily freshwater age 2 through 4 years (28.2, 23.1, and 28.2%, respectively), European origin fish were primarily freshwater age 2 (74.2%), and overall, 94.5% of the sampled fish were 1SW salmon. North American 1SW salmon averaged 66.6 cm with a mean whole weight of 3.20, and the 1SW mean length of European 1SW salmon was 65.6 cm with a mean whole weight of 3.38 kg. In 2021, the mean length of sampled fish was 66.6 cm, and the mean whole weight was 3.42 kg. North American origin fish were also primarily freshwater age 2 through 4 years (27.3, 38.3, and 21.7%, respectively), European origin fish were primarily freshwater age 2 (58.2%), and overall, 95.9% of the sampled fish were 1SW salmon. North American 1SW salmon averaged 66.2 cm with a mean whole weight of 3.34 kg, and the mean length of European 1SW salmon was 65.9 cm with a mean whole weight of 3.34 kg. Approximately 5,200 North American (17.2 t) and 3,600 European (13.7 t) salmon were harvested in 2020, and approximately 10,300 North American (34.4 t) and 2,000 European (7.4 t) salmon were harvested in 2021, not taking into account any unreported catch or reported harvest at East Greenland. Primary contributors to the sampled fish were the Gaspe Peninsula, the Gulf of St. Lawrence, and the Labrador South reporting groups (41 and 51% of the overall contribution in 2020 and 2021, respectively) for North American salmon and the United Kingdom/Ireland reporting group (42% and 16% of the overall contribution in 2020 and 2021, respectively) for European origin salmon. Travel restrictions associated with the COVID-19 pandemic significantly challenged the 2020 sampling program, and the sampling may not be wholly representative of the harvest across time and space. However, the samples do provide insights into the biological characteristics and origin of the harvested fish from this year. In 2021, the sampling program was2 successful, and the resulting data are considered representative of the entire harvest given the spatial and temporal coverage of the sampling.