After attending a Catholic school, he worked in a drawing office as a draughtsman before entering national service in the army.

Then, while working in a factory, he attended theatre acting evening classes, at which he met his life partner, James Culliford.

[2] In 1958 he joined the Royal Court Theatre and acted in a number of plays, including original productions of Chicken Soup with Barley and The Kitchen by Arnold Wesker.

Lynch also starred in Joan Littlewood's production of Brendan Behan's The Hostage in London and New York, in which critic Kenneth Tynan praised his "beautiful playing".

He appeared in a number of popular television series in later years including Jackanory, Going Straight, Bergerac, Lovejoy, Pie in the Sky and the Doctor Who serial The Curse of Fenric as Commander Millington.