Using a sharp, serrated knife, cut off and discard ends from oranges. Following the curve of the fruit, cut off peel and outer membrane. Slice oranges crosswise into 1/8-inch-thick rounds.
Hull and slice strawberries; add to oranges.
In a small bowl, stir together marmalade and lemon juice. Add to fruit and mix gently to coat.
Note: Nutritional analysis is per serving.