In a large nonstick skillet, heat the olive oil. Season the scallops with salt and pepper and cook over moderately high heat until golden brown on the bottom, 2 to 3 minutes.
Turn the scallops and cook until just opaque throughout, 2 to 3 minutes longer. Transfer to a platter and keep warm.
Melt the butter in the skillet. Add the sliced fennel and capers and cook over high heat, stirring, until the fennel is crisp-tender and lightly golden, 2 minutes.
Stir in the lemon juice and parsley and season with salt and pepper.
Spoon the fennel around the scallops and garnish with chopped fennel fronds. Serve with lemon wedges.
