Lundby hails from
Bøverbru and represents the
Kolbu KK ski club. She made her debut in the
Continental Cup, the highest level in women's ski jumping at the time, on 12 August 2007 with a 56th place in
Bischofsgruen. At age 14, she made history as the first female ski jumper in a World Championship, when she jumped with bib number 1 at the
FIS Nordic World Ski Championships 2009 in
Liberec. On 6 September 2010, she made the first jump when the new
Midtstubakken in
Oslo was opened. She landed on 87 meters. 14 March 2019, Lundby won the first women's edition of Raw Air. 12 March 2020, Lundby won the second edition of Raw Air and also became the first woman to win the World Cup three years in a row. She is the first ski jumper to do so since Adam Małysz in 2001–2003. On 3 March 2021, Lundby became the first female world champion on the large hill. In October 2021, Lundby withdrew from the
2022 Winter Olympics and said she had difficulties losing weight and did not feel she could perform at the top level. She was awarded the
Holmenkollen Medal in 2021. ==Major tournament results==