Lough Leane (Irish Loch Léin) is the largest of the Lakes of Killarney, with Mucross Lake and the Upper Lake upstream of it. The lakes lie in a mountain ringed valley starting in the Black Valley. The River Laune drains Lough Leane to the north towards Killorglin and into Dingle Bay

Various mountains ring the lake including:

• Carrantuohill (At 1039m/3409 ft, Ireland's highest mountain)
• Purple Mountain (2739 ft)
• Mangerton Mountain (2756 ft)

Ladies View is a scenic stopping point on the N71 road from Killarney to Kenmare that offers a view of the lakes and valleys.

Points of interest on Lough Leane include Innisfallen Island, Ross Castle and Muckross Abbey.

Muckross House is on the banks of Mucross Lake.

The lakes are renowned for their trout fisheries.