Bellamy attended the independent Tonbridge School and then Brasenose College, Oxford.

He spent a year teaching before starting to practise as a barrister in 1970,[2] when he joined Monckton Chambers.

He developed specialisms in European, competition and regulatory law, and in 1986 was appointed Queen's Counsel.

[2][4] After leaving the judiciary in 2007, Bellamy became a senior consultant at Linklaters, where he was appointed chairman of its Global Competition Practice in 2011.

[9] On 14 June 2022, to facilitate his ministerial role, he was created Baron Bellamy, of Waddesdon in the County of Buckinghamshire, for life, and was introduced to the House of Lords the same day, supported by Baroness Scott of Bybrook and Lord Anderson of Ipswich.