Republic of Sierra Leone, Africa

Sierra Entertainment, a computer game company that has created titles like Unreal Tournament 3

Sierra_online, Sierra On-line, Sierra Entertainment video game company

Ford Sierra, a car produced by the Ford Motor Company from 1982 to 1993, the successor to the Taunus/Cortina

Sierra Club, an environmental organization in the United States

GMC Sierra, a full-size pickup truck produced by General Motors

The NATO phonetic alphabet designation for the letter S

Ciara, American singer (pronounced like Sierra but with a different spelling)

Sierra (The Land Before Time), a character in The Land Before Time VII: The Stone of Cold Fire

Sierra County, California, in the north of the states

Jessica Sierra, American Idol 4 contestant

Sierra Semiconductor, a semiconductor company now known as PMC-Sierra

serra, Portuguese for mountain range

Rubén Sierra, a baseball player

Sierra Mist, a softdrink

Sierra Nevada Brewing Company, a California based brewery

Javier Sierra, Spanish journalist

Sierra Wireless, a wireless communications equipment manufacturer

Sierra-class submarine, a Russian attack nuclear submarine

Sierra de las Nieves, in Andalusia, Spain

Jamón serrano, Spanish for "Sierra ham"

Sierra (TV series), a 1974-1975 NBC television show that aired on Thursday nights

"Sierra," a song by Cursive from their 2003 album The Ugly Organ

High Sierra Trail, in California, United States

Sierra Valley, California, in Plumas and Sierra counties

Sierra Club of Canada, an environmental organization in Canada

Sierra Juarez and San Pedro Martir pine-oak forests, in Baja California, Mexico

Acme Sierra, a American experimental aircraft built in 1948

Sierra (porn star), an African-American erotic actress from Atlanta

Sierra National Forest, in California, United States

Sierra Systems, an information technology and business consulting company

Sierra Nevada National Park (Spain), in Andalusia, Spain

Sierra Bullets, an ammunition manufacturing company

Sierra Nevada Observatory, Granada, Spain

Sierra Nevada de Santa Marta National Park in northern Colombia