The new system applies to variants of concern - the most troubling of which four are in circulation - and the second-level variants of interest being tracked.
"They will not replace existing scientific names, but are aimed to help in public discussion," said Maria Van Kerkhove, the WHO's COVID-19 technical lead.
Under the new system, the variants of concern take on the following names: the hitherto so-called British variant B.1.1.7 becomes Alpha; the B.1.351 first discovered in South Africa becomes Beta, while the Brazilian P.1 becomes Gamma.
The so-called Indian variant B.1.617 is split into sub-lineages, of which the B.1.617.2 variant of concern becomes Delta.
The B.1.617.1 variant of interest is called Kappa.
Besides these names, there are two other scientific names in use for each mutation, while different geographic names have been used to describe the same variant.
For example, within Britain, what other countries have been referring to as the British variant is often called the Kent variant - the county in southeast England where it was first discovered.
The lineage names such as B.220.127.116.11 will still continue to be used in scientific circles, for the mutation information that their name conveys.
Stigmatizing and discriminatory
"While they have their advantages, these scientific names can be difficult to say and recall, and are prone to misreporting," the WHO said in a statement.
"As a result, people often resort to calling variants by the places where they are detected, which is stigmatizing and discriminatory.
"To avoid this and to simplify public communications, WHO encourages national authorities, media outlets and others to adopt these new labels."
No country should be stigmatized for detecting and reporting variants.— Maria Van Kerkhove (@mvankerkhove) May 31, 2021
Globally, we need robust surveillance for variants, incl epi, molecular and sequencing to be carried out and shared. We need to continue to do all we can to reduce the spread of SARS-CoV-2 #COVID19 @WHO
US anti-extremism groups say the number of attacks and hate crimes against Asian Americans has exploded since the beginning of the crisis.
They lay some of the blame with former president Donald Trump, who repeatedly referred to COVID-19 as the "China virus".
The WHO has been trying to come up with simplified new nomenclature for the variants for several months.
The Greek alphabet contains 24 letters but there is no plan yet as to where to go next if they are exhausted.
Epsilon, Zeta, Eta, Theta and Iota have already been ascribed to variants of interest.