Businessman Peter Casey came second with 23.1%, while none of the other four candidates polled more than 10%.
Earlier on Saturday, Sinn Féin leader Mary Lou McDonald said she was "disappointed" the party's candidate had not polled better.
Voters also supported the proposal to remove blasphemy as an offence from the Constitution, with 64.85% voting yes.
Mr Higgins, the first incumbent in 50 years to face a challenge in his bid for a second term, won with 822,566 votes.
Londonderry businessman Peter Casey took significantly more votes than the final opinion polls of the campaign had predicted. His final tally was 342,727.
Ms Ní Riada got 93,987 votes - 6.4% of the total votes polled.
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