Mark Lemon Romer, Baron Romer PC (9 August 1866 – 19 August 1944) was a British judge.
Invested to the Privy Council in 1929, he was Lord Justice of Appeal from 1929 to 1938. On 5 January 1938, he was appointed Lord of Appeal in Ordinary and was made additionally a life peer with the title Baron Romer, of New Romney in the County of Kent.
Both Lord Romer's father, Sir Robert Romer (1840-1918), and his son, Sir Charles Romer (1897-1969), were also judges, serving as Lords Justices of Appeal in 1899-1906 and 1951-1960 respectively. All three had served in the Chancery Division of the High Court.
His grandfather was Mark Lemon, founding editor of Punch magazine. He married Anne Wilmot Ritchie, daughter of Charles Thomson Ritchie.