Lake Harris, Freshwater lake in Central Florida, United States.

Lake Harris is a 13,788-acre freshwater lake in Lake County, Florida, 31 miles northwest of Orlando. It is the largest lake entirely within the county and forms part of the seven-lake Harris Chain. Its southwestern inflow comes from the Palatlakaha River, and its northeastern shore serves as a landing approach for Leesburg International Airport.

The area around Lake Harris was used by Seminole people before European settlers arrived in the 19th century and began farming and fishing along its shores. Over the course of the 20th century, water quality monitoring programs were introduced to keep track of the lake's ecological condition.

The lake's name honours Ebenezer Jackson Harris, a pioneer who lived at Yalaha on the south shore in the 1840s; before that it was called Lake Eustis after Colonel Abraham Eustis, and the Seminole name Astatula is also recorded. The modern Lake Eustis to the north, linked by the Dead River, now carries the colonel's name.

Three public launching ramps serve the lake: off U.S. Route 27 on the west side, at Venetian Gardens in Leesburg, and at Hickory Point near the Howey-in-the-Hills bridge off SR 19. A small ramp sits on the east side of Little Lake Harris in Astatula. Near the cattail and bullrush beds the water is only 2 to 5 feet deep, and the bottom is hard sand except in marshy spots.

Lake Harris is deep enough to allow motorboats and water skiing, which is unusual for this part of Florida where many lakes are too shallow for that kind of activity. This depth also means the water stays cooler longer into the warmer season compared to shallower lakes nearby.