Owned by iHeartMedia, KIIS-FM is the origin of the conglomerate's KISS-FM brand (with the call sign pronounced as "kiss"), and serves as the flagship station for the radio program On Air with Ryan Seacrest (although the KIIS version includes features not heard in the syndicated version, such as local traffic and weather as well as other locally relevant topics).

KIIS-FM's studios are located in Burbank, while the station transmitter resides on Mount Wilson, north of Los Angeles.

[2] As of December 2021, KIIS-FM is the only Top 40 station in the Los Angeles area, after Audacy's KNOU flipped to a simulcast of KNX and changed its callsign to KNX-FM.

[4] KRHM changed its call sign to KKDJ and flipped to contemporary hit radio (CHR, also known as Top 40) on April 15, 1971.

Making the transition from KKDJ to KIIS-FM were popular disc jockeys including Humble Harve, Jay Stevens, John Peters, Danny Martinez, and Charlie Tuna.

Tuna, an iconic voice of Los Angeles radio, served as both program director and morning show host for KKDJ and KIIS-FM at the transition; he died in February 2016.

In 1985, KIIS (AM) returned to a Top 40 format and simulcast KIIS-FM's morning and afternoon shows, while all other dayparts had different disc jockeys.

After Clear Channel's acquisition of KAVS and KYHT, the two High Desert stations abandoned their previous modern rock format and together began serving as repeaters for KIIS-FM.

Trade publication Radio & Records named KIIS-FM its 2007 "Station of the Year" in the contemporary hit radio/Top 40 category for market size 1–25 at its national convention.

On June 1, 2022, the KIIS-FM simulcast left SiriusXM, with the launch and establishment of the free iHeartRadio platform making the arrangement less important.

To accommodate the new role, it was announced that Seacrest would begin to host On Air from a studio constructed at the facilities of WABC-TV (where the TV show is produced).

In June 2019, KIIS-FM's HD2 subchannel stopped broadcasting the "Evolution" network and flipped to a simulcast of the analog audio with a 10-second delay.