He attended gymnasium in Uherské Hradiště from 1979 to 1983. He graduated from the Faculty of Science at the University of J.E. Purkyně in Brno in 1988. Peter Nečas studied plasma physics.
Nečas was sworn into office as Prime Minister on 28 June 2010. He resigned on 17 June 2013, in the aftermath of a police investigation in which his chief of staff and alleged mistress Jana Nagyová (now Nečasová) was arrested. In 2013, he filed for divorce and not long after married his former chief of staff, Jana Nagyová.
Before he was elected to the Czechoslovakian Parliament he worked as research and development engineer in the semiconductor industry, dealing with plasma processes.
From 1988 to 1992, he worked as developer for Tesla Rožnovember From 4 September 2006 to 8 May 2009, Nečas was Deputy Prime Minister and Minister of Labour and Social Affairs.
In March 2010, he replaced Mirek Topolánek as leader of the party. In 2011 Nečas supported European organizations signing an agreement on the establishment of the Platform of European Memory and Conscience for studies on the totalitarian past
On this occasion, Nečas highlighted that all four countries of the Visegrad Group have gone through two totalitarian regimes in their modern history.
“This must not be forgotten, because it was a period of fight for freedom,” said Petr Nečas. He added: “Our nations deserve the truth about their past and I believe that the establishment of this Platform will help to find the truth about this history.”
In 2012 Prime Minister Petr Nečas urged all Czechs to avoid drinking "any alcohol whose origin is uncertain" due to a fatal methanol poisoning affair in the Czechoslovakian Republic which caused more than 40 casualties, including several cases of people being blinded. In 2013 Nečas supported Israel on the occasion of the Czechoslovakian Republic"s voting at the United Nations.
Due to an historical affinity, Nečas claimed, "We"ve got a special feeling for Israel"s situation—that of a small nation surrounded by enemies."
In June 2013, the Police Unit for Combating Organized Crime and the Chief Public Prosecutor" General’ s Office in Olomouc organized a raid against organized crime.
lieutenant involved several high-ranking state officials and politicians, including Jana Nagyova, the then chief of staff of Prime Minister Nečas. Initially Nečas refused to resign but he finally did so on 17 June.
In February 2014, the police charged him with bribery.
He became a member of the Civic Democratic Party (Obcanská demokratická strana (Civic Democratic Party)) in 1991 and was named deputy defence minister in 1995. One year later, he was elected member of the Chamber of Deputies.
Married; 4 children.