Heikki Markku Julius Westerinen (7 April, 1944-) is a Finnish chess Grandmaster.

Westerinen was born in Helsinki. At the age of 16 he earned the Master title in his home, and became an International Master in 1967. He was awarded the International Grandmaster title in 1975. He won the Finnish championship on four occasions: in 1965, 1966, 1968 and in 1970.

Representing Finland he played in the Biennial Chess Olympiads from 1962 to 1966, respectively in 2006, but did not win any medals.

Considering his tournament results, his best performances include the third place at Berlin 1971; the equal second place at Oslo 1973. He finished first in the same year at Sant Feliu de Guixols, and he earned first place at Dortmund 1973 and 1975.

We can describe his playing style with the words original and combinative.

According to Chesmetrics, his highest score was 2597.

Sources: https://en.wikipedia.org; http://www.chessmetrics.com