At 2.46 pm, the exact moment the earthquake struck a decade ago, Emperor Naruhito and his wife led a moment of silence to honour the 20,000 dead in a commemorative ceremony in Tokyo. Silent prayers were held across the country.
After observing the moment of silence, Prime Minister Yoshihide Suga said it was still unbearable to contemplate the feelings of those who lost loved ones.
Attendees at the ceremony wore masks and kept their distance and did not sing along with the national anthem to prevent the spread of coronavirus.
“I would like to express condolences from the bottom of my heart to everybody who suffered from the effects of the disaster,” Mr Suga added.
Most of the casualties came when huge waves triggered by the 9.0 magnitude quake – one of the strongest on record – crashed into the northeastern coast.
A wave as high as 19m (62ft) was recorded in the town of Miyako in Iwate prefecture.
In Miyagi prefecture, the tsunami swept as far as 6km (3.6 miles) inland. The coastline impacted by the tsunami stretches for about 400km (240 miles).
The surge in water crippled the Fukushima Dai-chi power plant, forcing more than 160,000 residents to flee as radiation spewed into the air.
The world’s worst nuclear disaster since Chernobyl and the tremor have left survivors struggling to overcome the grief of losing families and towns to the waves in a few frightening hours on the afternoon of 11 March, 2011.
Emperor Naruhito and Mr Suga attended at a commemorative anniversary ceremony in Tokyo while several other events were planned across northeastern Japan, which was the worst hit.
The government has spent about 32.1 trillion yen to rebuild the region, but areas around the Fukushima plant remain off-limits, worries about radiation levels linger and many who left have settled elsewhere.
Decommissioning the crippled plant will take decades and billions of dollars.
About 5,000 workers pass through gates into the crippled plant each day to pull apart the plant, which still has about 880 tonnes of melted fuel debris in its reactors.
Some 40,000 people are still displaced by the disaster.