2008 (MMVIII) was a leap year that started on Tuesday of the Anno Domini era (or Common Era).

2008 was designated as:

• International Year of Planet Earth.
• International Year of Languages.
• International Year of the Potato.
• International Year of Sanitation.
• Year of the Frog.
• European Year of Intercultural Dialogue.

January

thumb|First-ever photograph of the "unseen side" of Mercury, taken by the MESSENGER spacecraft on January 14.

• January 1 – Cyprus and Malta adopt the euro.
• January 1 – A suicide bombing occurs in Zayouna, Baghdad, killing over 25 people during a funeral over the deaths from the preceding attack.
• January 2 – The price of petroleum hits $100 per barrel for the first time.
• January 3 – A car bomb detonates, killing at least 4 and injuring 68, in Diyarbakır, Turkey. Police blame Kurdish rebels.
• January 8 – An attempted assassination of Maldivian president Maumoon Abdul Gayoom is thwarted after a Boy Scout grabs the attacker's knife. The Boy Scout is injured, but after a scuffle police arrest the attacker.
• January 12 – A Macedonian Army Mil Mi-17 helicopter crashes in thick fog southeast of Skopje, killing all 11 military personnel on board.
• January 14 – At 19:04:39 UTC, the MESSENGER space probe is at its closest approach during its first flyby of the planet Mercury.
• January 15 – The Federal Court of Australia orders a Japanese whaling company to stop research whaling within their Exclusive Economic Zone.
• January 21 – Stock markets around the world plunge amid growing fears of a U.S. recession, fueled by the 2007 subprime mortgage crisis.
• January 22 – Russia stages the largest naval exercise since the fall of the Soviet Union in the Bay of Biscay. The Russian aircraft carrier Admiral Kuznetsov, along with 11 support vessels and 47 long-range bomber aircraft, practises strike tactics off the coast of France and Spain, and test-launches nuclear-capable missiles in foreign waters.

• January 23 – Polish Air Force EADS CASA C-295 crashes on approach to the 12th Air Base near Mirosławiec. All 20 personnel on board die.
• January 23 – Thousands of Palestinians cross into Egypt, as the border wall with Gaza in Rafah is blown up by militants.
• January 24 – A peace deal ends the Kivu war in the Democratic Republic of the Congo.
• January 25 – China's worst snowstorm since 1954 kills 133, delays traffic, and causes massive power outages in central and southern parts of the country.
• January 29 – Iran's judiciary sentences to prison 54 Bahá'í Faith followers for 'anti-regime propaganda'.

February