Peter Heine Nielsen (born 24 May 1973) is a Danish chess trainer and player.

He has won a record nine consecutive World Chess Championship titles as a coach, working with Viswanathan Anand in 2007, 2008, 2010, and 2012; then with Magnus Carlsen in 2013, 2014, 2016, 2018, and 2021.

Nielsen was awarded the title of International Master by FIDE in 1991 and that of Grandmaster in 1994.

He played for Denmark in seven Chess Olympiads, three times on top board, with an overall result of 60.1% (+24−10=35).

[1] On January 30, 2004 he played against ChessBrain – which earned the world record as the largest distributed chess computer.

Anand won the World Championship title in Mexico 2007, and defended it in Bonn 2008, Sofia 2010 and Moscow 2012.

[3] Carlsen won the Candidates Tournament 2013, which gave him the right to challenge Anand for the world championship.

In 2012 Nielsen began playing shogi; he achieved the mark of 2 dan in May 2017.

[4] Nielsen lives in Lithuania with his wife, Viktorija Čmilytė-Nielsen, and four children.

[5] Peter Nielsen vs. Henrik Danielsen, Danish Championship (playoff) 1996 1. c4 f5 2.