Who was president during the Iran-Contra scandal?

Ronald Reagan.

The Iran-Contra affair (or scandal) was thrust into public view during President Ronald Reagan's second term in office.

It all started as a plan to free American hostages in Lebanon. The Americans were held by a group that had connections to Iran. In an attempt to free the hostages some senior Reagan administration officials devised a plan with Israel and a religiously and politically moderate group in Iran. The plan was supposed to go like this: Israel was to send weapons to the Iranian group then the U.S. was to resupply Israel and Israel was to pay the U.S. for the weapons that they received while the Iranians attempted to free the hostages.

This plan was, of course, all illegal. Due to the political lability and hostility of Iran at the time, the U.S. had an arms embargo on Iran (no weapons were allowed to be sold or given to the Iranians). This posed a problem for Reagan administration officials, there was a money trail. They needed to get rid of the money.

How did they get rid of it you ask? The best way they knew how.

A Lieutenant Colonel by the name of Oliver North and several other top officials on the National Security Council decided to use it to fight the communist government in Nicaragua. An anti-communist group called the Contras was the prime beneficiary of the money. Essentially the U.S. was funding a civil war in Nicaragua.