Tennyson excelled at penning short lyrics, including "In the valley of Cauteretz," "Break, break, break", "The Charge of the Light Brigade", "Tears, idle tears" and "Crossing the Bar". Much of his verse was based on classical mythological themes, although In Memoriam A.H.H. was written to commemorate his best friend Arthur Hallam, a fellow poet and classmate at Trinity College, Cambridge, who died at the age of 22. Tennyson also wrote some notable blank verse including Idylls of the King, Ulysses, and Tithonus.

Tennyson wrote a number of phrases that have become commonplaces of the English language, including: "nature, red in tooth and claw", "better to have loved and lost", "Theirs not to reason why, / Theirs but to do and die", and "My strength is as the strength of ten, / Because my heart is pure". He is the second most frequently quoted writer in The Oxford Dictionary of Quotations, after Shakespeare.