Yelü Lübugu (Chinese: 耶律呂不古) or known by the title Princess of Yan State (Chinese: 燕国公主), was a Liao dynasty princess and the first daughter of Emperor Taizong of Liao. She then married Prime Minister Xiao Siwen and bore him the three Xiao Sisters (Xiao Hunian, Lady Xiao and Xiao Yanyan). However, she died from her illness. Her youngest daughter Xiao Yanyan married with Yelü Xian and in 969 and become the Liao empress. The Xiao family was the consort kin of the Liao dynasty, all future empresses and imperial brides originating from this faction.