Lilleholt is a member of the liberal Venstre Party, which formed a minority government following the election on 18 June.
The election results meant Venstre slipped from being the second-largest party in the Danish Parliament to third. Venstre is however, the lead party in the "blue bloc" of centre-right parties in Denmark.
Venstre formed a minority government after "blue bloc" parties were unable to form a majority coalition government. Its leader, Lars Lokke Rasmussen has become prime minister.
Lilleholt replaces Rasmus Helveg Petersen of the Danish Social Liberal Party, who was in office since February 2014. Lilleholt had previously been the energy spokesperson for his party.
Vestas policy specialist Ask Møller-Nielsen welcomed the new energy minister: "We support the government's ambition to make Denmark completely independent from fossil fuels no later than 2050, and we believe wind can play a pivotal role in making this happen.
"Lars Christian Lilleholt is a very experienced and respected politician who has been part of the broad political agreements on energy for the past ten years. We look forward to continuing the good cooperation with him, and fully expect the new government to maintain Denmark's leading position on wind energy," he added.
FTI Consulting head of wind energy Feng Zhao said energy policy is unlikely to change under the new government as all parties have signed up to ending the use of fossil fuels in the country by 2050.
Denmark added 126MW of new onshore capacity in 2014 and decommissioned 29MW, raising the total onshore fleet by a net 97MW to 3.63GW. Including 1.27GW offshore, Denmark had a total 4.9GW in operation at the end of 2014.
In January, Denmark's energy ministry released figures showing 39.1% of its electricity in 2014 came from wind. This figure has more than doubled in ten years: in 2004 wind accounted for 18.8% of the country's electricity production.