|Born|| June 3, 1993
|Peak rating||2647 (October 2015)|
Nils Grandelius (born June 3, 1993 in Lund) is a Swedish chess grandmaster.
He became a FIDE master in 2007, an International Master in 2008 and a Grandmaster (GM) in 2010.
In 2008, Grandelius tied for second place, placing fourth on countback, in the Under-16 European Youth Championship. In the same year, he took clear first place in the Olomouc Open in Czech Republic with a score of 6.5 points out of 9 games; thanks to this result, he also achieved his first GM norm. In the following year's edition, he placed equal first with the same score, placing second on tiebreak, and gained the second GM norm. He achieved the GM title by earning the third and final norm in the 40th Bosna International Tournament in Sarajevo, in which he finished fifteenth, the first among juniors.
He won the bronze medal at the 2010 World Under-18 Championship.
Grandelius won the 2011 European Under-18 Championship in Albena, Bulgaria.
In May 2012, he placed third in the 20th Sigeman & Co Chess Tournament in Malmö, behind the winner Fabiano Caruana and the runner-up Peter Leko. Later that year, in August 2012, he placed equal third (fourth on tiebreak) in the World Junior Championship in Athens.
He has been trained by Evgenij Agrest since 2013.