Nicaragua Human Rights and Anticorruption Act of 2018 This bill directs the President to impose through December 31, 2021, property-blocking and U.S. entry sanctions against any foreign person, including any current or former Nicaraguan government official, who: has perpetrated or is responsible for directing significant acts of violence or human rights violations in Nicaragua against persons associated with the protests that began on April 18, 2018; is responsible for or complicit in directing significant actions or policies that undermine democratic processes or institutions in Nicaragua; or is a government official or a senior associate of such official who is responsible for or complicit in directing acts of significant corruption. The President may waive such sanctions for a one-year period if the Department of State certifies to Congress that Nicaragua is taking steps to strengthen democracy, combat corruption, and protect the rights of journalists and opposition political parties.