The exact purchase price of her three-bedroom, three-bathroom unit was not available, but prices in the five-story building range from $800,000 to $2 million.
Amenities include a full-time concierge, round-the-clock staffing, a fitness facility and a swimming pool.
Olsen, who also owns a home in Utah, plans to divide her time between that house, her Pasadena condominium and traveling.
Merlin Olsen, who died last year at 69, was a former NFL player and commentator. He was a defensive lineman for the Los Angeles Rams from 1962-76. He went on to star in "Little House on the Prairie" (1977-81).