February 5 – The Argentine president Isabelita Perón decrees Operativo Independencia, aiming to neutralize or annihilate the "subversive elements" in the province of Tucuman. Isabelita takes advantage to take a self-coup and assume extraordinary powers.
March 22 – Ding-a-dong by Teach-In (music by Dick Bakker, text by Will Luikinga and Eddy Ouwens) wins the 20th Eurovision Song Contest 1975 for the Netherlands.
March 27 – The South African government announces that it will consolidate the 113 separate homeland areas into 36.
March 28 – A fire in the maternity wing at Kucic Hospital in Rijeka, former Yugoslavia, kills 25 people.
March 29 – Blow by Blow by Jeff Beck is released. It would become his most successful album in the United States, reaching the top five and selling over one million copies.
Süleyman Demirel of AP forms the new government of Turkey (39th government, a four-party coalition, so-called First National Front (Turkish: Milliyetçi cephe)).
In his final game on the sideline, John Wooden coaches UCLA to its 10th national championship in 12 seasons when the Bruins defeat Kentucky 92-85 in the title game at San Diego.
April 5 – The Soviet manned space mission Soyuz 18a ends in failure during its ascent into orbit when a critical malfunction occurs in the second and third stages of the booster rocket during staging, resulting in the cosmonauts and their Soyuz spacecraft having to be ripped free from the vehicle. Both cosmonauts survive.
April 15 – Karen Ann Quinlan, 21, faints after consuming Quaaludes at a party. She becomes a controversial subject in the right to die movement after her parents sue to have her comatose body removed from life-support. She lives off a feeding tube until 1985.
April 24 – Six Red Army Faction terrorists take over the West German embassy in Stockholm, take 11 hostages and demand the release of the group's jailed members; shortly after, they are captured by Swedish police (See West German Embassy siege).
May 3 – West Ham United wins the FA Cup at Wembley, beating Fulham 2–0 in the final. Both goals are scored by Alan Taylor. West Ham legend Bobby Moore, appears for Fulham.
May 15 – Mayaguez incident: The American merchant ship Mayaguez, seized by Cambodian forces, is rescued by the U.S. Navy and Marines; 38 Americans are killed.
June 10 – In Washington, D.C., the Rockefeller Commission issues its report on CIA abuses, recommending a joint congressional oversight committee on intelligence.
June 11 – After a referendum and seven years of military rule, modern day Greece is established as the Hellas Republic.
The first Cuban forces arrive in Angola to join Soviet personnel who are there to assist the MPLA that controls less than a quarter of Angolan territory.[6]
August 5 – U.S. President Ford posthumously restores the U.S. citizenship of General Robert E. Lee, military leader of the Confederate States of America during the American Civil War.
Some members of Jehovah's Witnesses believe that Armageddon will occur this year based on the group's chronology[7] and some sell their houses and businesses to prepare for the new world paradise which they believe will be created when Jesus establishes God's Kingdom on Earth.
August 24 – Officers responsible for the military coup in Greece in 1967 are sentenced to death in Athens. The sentences are later commuted to life imprisonment.
September 15 – The French department of "Corse", comprising the entire island of Corsica, is divided into two departments: Haute-Corse (Upper Corsica) and Corse-du-Sud (Southern Corsica).
October 14 – The South African Defence Force invades Angola during Operation Savannah in support of the FNLA and UNITA prior to the Angolan elections scheduled for 11 November.[9]
Tun Mustapha resigned as Chief Minister of Sabah, a state in Malaysia, bringing to an end speculation that he would attempt to lead secession for Sabah to become an independent nation.
An independent audit of Mattel, one of the United States' largest toy manufacturers, reveals that company officials fabricated press releases and financial information to "maintain the appearance of continued corporate growth."
November 7 – A vapor cloud explosion at a petroleum cracking facility in Geleen, Netherlands leaves 14 dead and 109 injured, with fires lasting for five days.
While disabled, the submarine tender USS Proteus discharges radioactive coolant water into Apra Harbor, Guam. A Geiger counter at two of the harbor's public beaches shows 100 millirems/hour, 50 times the allowable dose.
Formula One world champion Graham Hill is killed when the Piper Aztec aeroplane he was piloting crashed in foggy conditions near Arkley golf course in North London.
The Spanish Army quits Spanish Sahara (modern-day Western Sahara), last remnant of the Spanish Empire. The Sahrawi Republic (RASD) is created. Morocco invades the former territory.