Francis also laid flowers at the monument and is believed to have met descendants of the Armenian orphans Pope Pius XI housed at his summer home south of Rome during the 1920s.
The pontiff prompted a standing ovation on Friday when he labelled what he described as the ideologically warped, planned "genocide" of Armenians beginning in 1915.
He strayed from a prepared speech to use the politically-charged term and made the claim, which Turkey has previously rejected.
Francis is on a three-day visit to Armenia during a tour of Caucasus region which will also see him travel to Georgia and Azerbaijan.
He met with the Armenian President Serzh Sargsyan in Yerevan's Presidential Palace on Friday and Catholicos Karekin II at the Apostolic Cathedral of Etchmiadzin.
Following his visit to the genocide memorial, the Pope is due to travel Gyumri in the north-west of the country, where he will hold his only public Catholic Mass and a prayer for peace.