Alpaida (also Alpaïde, Alpaide, Alphaida, Alpoïde, Elphide, Elfide, Alféïde, Chalpaida; c. 654 – c. 714) was a Frankish noblewoman who hailed from the Liège area. She became the second wife, concubine or mistress of Pepin of Herstal and mother to his son Charles Martel and possibly another, Childebrand I.

In the Liber Historiae Francorum and the Continuations of Fredegar she is referred to as Pepin's wife.

Saint Lambert of Maastricht was a vocal critic of the relationship between Pepin and Alpaida. A tradition would eventually develop that, Pepin's domesticus (manager of state domains) Dodon, whose troops would murder Lambert, was in fact the brother of Alpaida; however, the historical accuracy of Dodon being her brother has been questioned.