Rowena (foaled 1817) was a British Thoroughbred racehorse and broodmare that won the classic 1000 Guineas at Newmarket in 1820.
Rowena was a chestnut mare bred by her owner George FitzRoy, 4th Duke of Grafton at his stud at Euston Hall in Suffolk.
According to the Sporting Magazine, Rowena "won easy", beating Mr Wyndham's unnamed filly that had been made the 5/2 second favourite.
The Epsom meeting was badly affected by stormy weather, with heavy rain and strong winds, resulting in a much reduced attendance for both the Derby on Thursday and the Oaks a day later.
Rowena finished second to Caroline, which reversed the 1000 Guineas form to win by a length with Bombasine third and Emmeline unplaced.