Klinec made her international debut at the Ladies Cup in summer 2010 . She won all five competitions where she started and in the end she finished third behind Anna Rupprecht and Katharina Althaus in the overall ranking. Due to this good performance, Klinec made her debut in the Continental Cup on January 22, 2011 in Ljubno and immediately took 16th place. In the second competition, Klinec was eighth. In this season they also went in the Continental Cup in Zakopane and Ramsau am Dachstein at the start and reached in all four competitions the second round. At the 2011 OPA Games in Baiersbronn , Klinec won the silver medal.
In the summer of 2013, Ema Klinec was used for the first time at the highest competition level at the Tremplin du Praz facility in Courchevel as part of the 2013 Ski Jumping Grand Prix and was able to win straight away. On September 14th and 15th, 2013 she won the two COC competitions in Lillehammer and thus also won the summer COC competition. At the start of the 2013/14 World Cup season in Lillehammer, she made her World Cup debut in the mixed team competition on December 6, 2013 and finished fifth with the Slovenian team. The following day she made her debut in the individual and jumped straight into the top ten in seventh place. In four other World Cup starts this season, she jumped three more times in the top ten with fifth place in Tchaikovsky as the best result. On January 10, 2014, she won the Alpine Cup jumping in Predazzo . At the competition the following day, she fell in the trial run and tore ligaments in her right knee. As a result, she missed the 2014 Winter Olympics in Sochi and the entire 2014/15 season.
She made her international comeback after her injury on July 11th and 12th, 2015 at the FIS-Cup jumping in Villach . In the first competition she was disqualified and the following day she was third. Then she finished 15th at the Summer Grand Prix in Courchevel and jumped first and second on the podium at the Continental Cup competitions in Oberwiesenthal . On January 16, 2016, she achieved her first podium finish in the World Cup in second place in Sapporo . In the further course of the World Cup season, she reached two more placements on the podium. In the overall World Cup of the 2015/16 season, she finished ninth with 426 points, making it into the top ten for the first time. At the 2016 Winter Youth Olympic Games in Lillehammer , she won both the individual competition and the mixed team competition with the Slovenian team. At her third Nordic Junior World Ski Championships in 2016 in Râşnov , she was sixth in singles and world champion in mixed team competition.
At the Slovenian Championships in Planica in 2016 , she won the silver medal behind Maja Vtič and ahead of Eva Logar . In the 2016/17 World Cup season , she achieved two more podium finishes as second in Oberstdorf and third in Pyeongchang . In the overall World Cup of the 2016/17 season, she finished seventh with 630 points and thus achieved her best placement to date. At her fourth Nordic Junior World Ski Championships in 2017 in Park City , she won a medal in all three competitions in which she competed. She won the silver medal in the individual and team competition as well as the gold medal in the mixed team competition. A few weeks later she took part in the 2017 Nordic World Ski Championships in Lahti . She finished fifth in the singles and fourth with the Slovenian mixed team.
At the Slovenian Championships in 2018 , Klinec started as the defending champion and favorite, but fell on December 23, 2018 while landing on her second jump on the large hill in Planica and tore a cruciate ligament with cartilage damage in her left knee. This meant the premature end of the season.
In mid-September 2019, Klinec started an international competition at the Continental Cup in Stams for the first time after her injury. While she narrowly missed the podium in fourth place, the next day she celebrated her fifth Continental Cup victory in front of Marita Kramer and Urša Bogataj . Also at the beginning of the 2019/20 World Cup , Klinec immediately caught up with the world's best and after two fourth places in Lillehammer was even able to reach the podium in Klingenthal in second place. In mid-December she also became the Slovenian champion in Planica .