Raisi is a hardline judge who spent years in powerful backroom positions before emerging as a leading challenger for Iran's presidential election next month.
Beside Ahmadinejad, moderate Rouhani, backed by a group of reformists will have to fight off the challenge from Ebrahim Raisi.
He filed his candidacy after Iran's President Hassan Rouhani ended weeks of speculation by signalling his intention to seek a second term.
During Ahmadinejad's administration, Iran faced heavy global sanctions for its nuclear program, which Western countries said aimed to develop weapons. At least 120 people have registered as candidates.
Rouhani also highlighted the importance of resistance. Others include a brother of late President Akbar Hashemi Rafsanjani and Tehran's mayor.
Under Iran's Constitution, a president can not serve for three terms in a row.
USA considers shooting down N.Korea missile tests
In 2005, those talks produced an agreement that might have led to a denuclearized Korean Peninsula. That two-week window overlaps with North Korea's military foundation day on April 25.
Human rights campaigners say there have been few, if any, moves to bring about greater social freedoms as Rouhani's main focus has been boosting the sanctions-damaged economy.
President Donald Trump has frequently criticized the nuclear deal with Iran.
More than 950 people have signed up so far. Iranian conservative cleric Ebrahim Raisi representing the Popular Front of Islamic Revolution Forces (JAMNA) has registered to run in the presidential election due on May 19, the ISNA news agency reports.
Ahmadinejad previously served two four-year terms from 2005 to 2013.
He was also Prosecutor and Deputy Prosecutor of Tehran in 1980s and 1990s. Several former ministers and hardline former president Mahmoud Ahmadinejad are among those who have registered.
Rouhani's defended the policy of 'strengthening the defensive prowess of Iran's Armed Forces'.
Secret Service beefs up barriers at White House
On the map below, the upper arc represents the old fence line; the lower arc represents the new boundary for the public. Secret Service Communications Director Cathy Milhoan said on Wednesday "that vantage point.is still there".
"Those who are the directors must give the role (of president) to a person who can pull it off best", said Ahmadinejad.
According to Shakdam, Ahmadinejad's decision to run was not an act of defiance but simply a choice based on his willingness to offer a "different kind of a flavor in politics" and ensure that the voices of his faction are heard, especially in the context of the current tension between the US, Iran and Russian Federation, and around the Middle East in general.
Ahmadinejad on Wednesday described comments by the supreme leader as "just advice" in a news conference shortly after submitting his registration.
The Guardian Council will assess the qualification of the applicants and announce the names of the qualified candidates by April 27.
It is not clear if Mr. Ahmadinejad intends to stay as a candidate or plans to shape the election agenda in favour of the hardliners.
Canadian Defence minister Harjit Singh Sajjan visits Harmandir Sahib
Amarinder Singh remained adamant on not meeting Sajjan despite the Canadian minister proposing a meeting. The Canadian Defence Minister is a Sikh whose native village of Bambeli falls in Hoshiarpur district.