Eliard Swanston (died 1651), alternatively spelled Heliard, Hilliard, Elyard, Ellyardt, Ellyaerdt, and Eyloerdt, was an English actor in the Caroline era. He became a leading man in the King's Men, the company of William Shakespeare and Richard Burbage, in the final phase of its existence.
Swanston started his acting career with Prince Charles's Men around 1620. In 1622 he moved to the Lady Elizabeth's Men, and two years later transferred to the King's Men. He may have been brought into that company to replace the veteran John Underwood, who died in 1624. By 1631 he had acquired a role in the management of the company, along with Joseph Taylor and John Lowin; the three men received the company's payments for their performances at Court. In some cases, Swanston was the sole payee for the King's Men's Court performances; he received sums of £120 (February 1632), £270 (March 1633), and £220 (April 1634), and other amounts, in trust for the company. Being a leader was not wholly positive: on 24 October 1633, Swanston and Lowin had to apologize to Sir Henry Herbert, the Master of the Revels, for performing a play without Herbert's approval.
Swanston gradually came to play some of the leading Shakespearean roles in revivals, including the title parts in Othello and Richard III. In the late 1630s he played the title character in George Chapman's Bussy D'Ambois, after the previous actor in the role, Taylor, had grown too "grey" for the role of a young firebrand. Swanston also originated some of the leading roles in the company's productions of Philip Massinger's plays. He played the role of Lugier, "the rough and confident tutor to the ladies," in a 1632 revival of Fletcher's The Wild Goose Chase. He was Melantius in revivals of The Maid's Tragedy, and may have played the lead in Philaster. He played Aretine the spy in The Roman Actor, and had roles in other Massinger plays, The Picture and Believe as You List; he played the young lover Alcidonus in Arthur Wilson's The Swisser (1631).