Ghani, who was elected in a fraud-tainted poll in 2014 that was only resolved in a US-brokered power-sharing deal, is expected to present himself to war-weary voters as the candidate who can end the 17-year conflict.
The 69-year-old acerbic academic, who has a reputation for shouting at subordinates and micromanaging the unity government, will try to capitalise on renewed US-led efforts to engage the Taliban in peace talks, which are showing tentative signs of bearing fruit.
"I can confirm that President Ghani is seeking re-election next year," presidential palace spokesman Shah Hussain Murtazawi told AFP.
Ghani, who chose the widely feared ethnic Uzbek leader Abdul Rashid Dostum as his first running mate in the 2014 election, has not yet announced who he will pick this time round.
It also is not certain who will challenge Ghani in the April 20 ballot.
Chief Executive Abdullah Abdullah, Afghanistan's equivalent of prime minister, and former national security adviser Mohammad Haneef Atmar, who quit in August, are among potential contenders.
Former Balkh provincial governor Atta Mohammad Noor, whose refusal to stand down from his position sparked a months-long political crisis for Ghani, has previously expressed interest in the job.
Nominations open on November 10.
The embattled Independent Election Commission (IEC) had been scheduled to release the results of last month's shambolic parliamentary poll on the same day, but on Saturday pushed back the date until November 23 for all provinces except Kabul.
Kabul province's results would be released on December 1, IEC spokesman Sayed Hafizullah Hashimi told reporters.
Ghani, an ethnic Pashtun, will need more than the support of Afghanistan's largest ethnic group if he is to succeed at the ballot box and he has already started trying to win over rival ethnicities.
Vice President Dostum's controversial return from exile in July was interpreted as an attempt by Ghani to secure votes from the minority group.
Ghani's presidency has been marred by growing militant violence, record-high civilian casualties, political infighting, deepening ethnic divisions, and fading hopes among Afghans.
The results of a Gallup survey released last month showed unprecedented levels of pessimism among people in the war-torn country.
Ghani, an American-educated former World Bank official, took office in 2014 as US-led NATO combat troops withdrew from the country, sparking a resurgence in the Taliban which also coincided with the emergence of the Islamic State group in the region.
In February, under growing pressure from the international community which provides critical financial and military backing to the government, Ghani made a peace offer to the Taliban.
That was followed in June by an unprecedented ceasefire between Afghan troops and Taliban fighters that lasted three days and spurred hopes that peace was possible.
Taliban representatives have met with US officials at least twice in Qatar in recent months, most recently on October 12 with newly appointed US peace envoy Zalmay Khalilzad.
Khalilzad also is in talks with regional countries, including Pakistan and Saudi Arabia, to coordinate efforts to get the Taliban to the negotiating table.