Sikera Valley (Bulgarian: долина Сикера, ‘Dolina Sikera’ \do-li-'na si-'ke-ra\) is an ice-filled valley spanning 17 km long and 5.7 km wide. The valley is located between Doyran Heights and Flowers Hills on the east side of Sentinel Range in Ellsworth Mountains, Antarctica. A nameless steep 4-km side glacier drains northeastwards from Mount Havener in Doyran Heights, and empties into the upper part of the valley, south of Kostinbrod Pass. The valley ice flows southeastwards towards the Rutford Ice Stream.
The feature is named after the medieval fortress of Sikera in southeastern Bulgaria.