Septimus Drummond "Sep" Lambert (3 August 1876 in Dublin, Ireland – 21 April 1959 in Dublin) was an Irish cricketer.
A right-handed batsman and wicket-keeper, he played 14 times for the Ireland cricket team between 1896 and 1921, including seven first-class matches.Lambert was educated at Rathmines School and Wesley College in Dublin and at St John's College in Preston before qualifying as a solicitor in Dublin.