In 1965, Leander was part of Matchmaker I, a multi-national squadron of NATO, and the predecessor of Standing Naval Force Atlantic (STANAVFORLANT), which was created in 1967, although it was not actually formed until the following year.

In June that year, Leander began modernisation that included the removal of her one twin 4.5-in gun which was replaced by the Ikara anti-submarine warfare (ASW) missile launcher.

The TG, upon reaching their destination performed a number of exercises and 'fly the flag' visits with Far East and Pacific countries.

In December 1975, Leander, under the command of Captain John Tait, began a Fishery Protection Patrol during the Third Cod War between the United Kingdom and Iceland over fishing disputes.

Þór sailed back to port for repairs with her helicopter deck damaged, while Leander's hull was dented on her starboard bow.

[1] In 1977, Leander undertook a refit, and the following year headed to the West Indies, California, British Columbia, Mexico and Florida.

Her career came to an end in 1989, when during a naval exercise, she was sunk by a Sea Dart missile, three Exocets and one gravity bomb.