Frome grammar school. Apprenticed to a surgeon at Plymouth, he made unsuccessful application for employment at the Plymouth Theatre, and then joined, at fifteen shillings a week, the Norwich company. After two years spent in playing insignificant parts, he came to London, and was accorded leading business at the Richmond Theatre. Applications to the managements at Drury Lane and Covent Garden being fruitless, he obtained an engagement in Dublin. In 1761–2, at Smock Alley Theatre, he played, under Mossop, Etan in the ‘Orphan of China.’ In 1762 Reddish went to Crow Street, where, in 1763, he appeared as Young Clackit in the ‘Guardian.’ In Ireland he stayed some years, obtaining artistic and social recognition as a gentleman of easy fortune, but running deeply into debt. The author of ‘Theatrical Biography,’ 1772, tells at considerable length of a shameful trick he played his creditors. He persuaded them to take tickets for his benefit in ‘Richard III,’ promising to repay the remainder of their debts out of the receipts. On the tickets thus given being presented at the theatre, their holders were refused admission. The angry creditors assembled next day, but found that Reddish had disappeared with the proceeds of the entertainment.
Reddish made his first appearance at Drury Lane as Lord Townly in the ‘Provoked Husband’ on 18 Sept. 1767. On the 23rd he was Lord Falbridge in the ‘English Merchant,’ on 10 Oct. Posthumus, and on 23 Oct. George Barnwell in the ‘London Merchant.’ Lovewell in the ‘Clandestine Marriage,’ Moneses in ‘Tamerlane,’ King Edward in the ‘Earl of Warwick,’ Etan, Castalio in the ‘Orphan,’ Raymond in the ‘Countess of Warwick,’ Heartley in the ‘Guardian,’ Fainall in the ‘Way of the World,’ Orlando in ‘As you like it,’ Richard III (for his benefit), Antonio in the ‘Merchant of Venice,’ Macduff to the Macbeth of Garrick, Edgar in ‘Lear,’ Theodosius in the piece so named were given during his first season; he was also the original Frederick Melmoth in Kenrick's ‘Widow'd Wife’ on 5 Dec. 1767, and Lord Winworth in Kelly's ‘False Delicacy’ on 23 Jan. 1768.
Reddish remained during ten seasons in all at Drury Lane, playing many important parts, Alexander the Great, Alonzo in the ‘Revenge,’ Dumont, Southampton in ‘Earl of Essex,’ Henry VI to the Richard III of Garrick, Lord Aimworth, Lothario, Jupiter in ‘Amphitryon,’ Oakly, Valentine in ‘Love for Love,’ Osman in ‘Zaro,’ Sir Charles Easy in ‘Careless Husband,’ Young Bevil in ‘Conscious Lovers,’ Young Belmont in the ‘Foundling,’ Iago, Clerimont in the ‘Tender Husband,’ Leon in ‘Rule a Wife and have a Wife,’ King Arthur, Beverley in the ‘Gamester,’ Lord Wronglove in ‘Lady's Last Stake,’ Varanes, Bajazet, Osmyn in ‘Mourning Bride,’ Jaffier, Macbeth, Tancred, Alfred, King John, Hippolitus in ‘Phædra,’ Earl of Warwick, Antony in ‘All for Love,’ Evander, Claudio in ‘Measure for Measure,’ Vainlove in the ‘Old Bachelor,’ Falkland in the ‘Rivals,’ and other characters. He was seen in a good many original parts, principal among which were Darnley in the ‘Hypocrite,’ Frampton in Mrs. Griffith's ‘School for Rakes,’ Orellan in Home's ‘Fatal Discovery,’ Sir John Dormer in Kelly's ‘Word to the Wise,’ Don Carlos in Bickerstaffe's ‘'Tis well it's no worse,’ Tyrrel in Cumberland's ‘Fashionable Lover,’ Philotas in Murphy's ‘Grecian Daughter,’ Young Melville in O'Brien's ‘Duel,’ Alonzo in Home's tragedy so named, Belville in Kelly's ‘School for Wives,’ Menes in Dow's ‘Sethona,’ Count Alberti in ‘Heroine of the Cave’ (begun by Henry Jones, 1721–1770 [q. v.], under the title of ‘The Cave of Idra,’ and left by him in the hands of Reddish, who induced Paul Hiffernan [q. v.] to finish it), Charles Manlove in Cumberland's ‘Choleric Man,’ Morcar in Dr. Francklin's ‘Matilda,’ Duke of Braganza in Jephson's ‘Braganza,’ Oroes in Ayscough's ‘Semiramis’ (adapted from Voltaire), and Young Fashion in Sheridan's ‘Trip to Scarborough.’ In 1777–8 he was not engaged.
On 12 Oct. 1778 Reddish made, as Hamlet, his first appearance at Covent Garden. He repeated his performances of Posthumus, a character in which, ‘by particular desire,’ he was again seen for his benefit on 5 May 1779. This was his last appearance on the stage. He had long given signs of failing memory. On 9 March 1779 he forgot his engagement to play the original character of Alonzo, and the part had to be read on the stage by another actor. With a view to setting himself right with the public, he issued, together with an apology, an affidavit concerning his forgetfulness. Two months later his friends prevailed upon the management of Covent Garden to give him a benefit, in which he was to play Posthumus. Early in the day he betrayed signs of idiocy, and asserted that he was about to play Romeo (Letters and Poems of the late Mr. John Henderson, ed. John Ireland, p. 48 n.). With difficulty he was disabused of the idea and pushed on to the stage. In presence of the public his countenance resumed meaning, and, though in the green-room he kept relapsing into Romeo, he played Posthumus through on the stage better than was customary, his manner being ‘more natural and less assuming.’ For some