Henry Dillon, 8th Viscount Dillon (died 1713) was Lord Lieutenant of Roscommon.
He managed to obtain a reversal of the outlawry against his deceased father, Theobald, the 7th Viscount in 1694, and later served as Lord Lieutenant of County Roscommon.
He died in 1713, leaving one son, Richard, 9th Viscount, whom died in 1737, without male issue, and the title passed to the 8th Viscount's nephew, his brother Arthur's son, Charles. Charles also died without male issue in 1741, and the viscountcy passed to his brother Henry Dillon, 11th Viscount Dillon.