Hello Sunshine, the media company founded by actress and entrepreneur Reese Witherspoon whose titles include the hit HBO drama “Big Little Lies,” is exploring a sale, according to people familiar with the matter.

The company began pursuing a sale in recent months after receiving interest from multiple suitors including Apple Inc., one of the people said. People close to the situation say the company could be valued at as much $1 billion in a deal.

Hello Sunshine is working with investment bankers as it explores its options, the people familiar with the matter say. There is no guarantee the company will find a buyer.

Hello Sunshine’s production slate also includes Hulu’s “Little Fires Everywhere,” a limited series starring Ms. Witherspoon and Kerry Washington as mothers in suburban Ohio, and Apple’s “The Morning Show,” which stars Ms. Witherspoon and Jennifer Aniston as morning show hosts.

Hello Sunshine is owned by Ms. Witherspoon and her partners, Seth Rodsky and Jim Toth, a former agent at Creative Artists Agency who is Ms. Witherspoon’s husband. The company’s management team also has equity in the venture.

AT&T Inc. also owns a stake in Hello Sunshine through its 2018 purchase of Otter Media. Emerson Collective, the philanthropic organization founded by Laurene Powell Jobs, also owns a stake.

Hello Sunshine doesn’t disclose its finances. Time magazine reported in April that the company expected to be profitable for the first time this year.

Hello Sunshine could be an acquisition target for streaming-video companies looking to add high-profile titles. Streaming companies have been racing to better compete with heavyweights such as Netflix Inc. and Walt Disney Co. Hollywood studio MGM agreed to sell itself to Amazon.com Inc. in late May for around $6.5 billion. Earlier in May, AT&T and Discovery Inc. reached a deal to combine their media assets into a new, publicly traded company.

A sale of Hello Sunshine would be a milestone in Ms. Witherspoon’s three-decade career, which has included major roles in films including “Legally Blonde,” “Wild” and “Election.” Ms. Witherspoon won the Academy Award for best actress in 2006 for her performance as June Carter in “Walk the Line,” the 2005 biopic of country music legend Johnny Cash.

Hello Sunshine also has a popular book club, Reese’s Book Club, which earlier this year introduced a free app, and Ms. Witherspoon frequently uses her Instagram feed to promote its monthly books. Hello Sunshine receives a portion of the revenue from book purchases that result when members click through to e-commerce sites from its app. The company has corporate partnerships as well.

—Lillian Rizzo contributed to this article.

Write to Benjamin Mullin at Benjamin.Mullin@wsj.com and Cara Lombardo at cara.lombardo@wsj.com