Rod Rosenstein, the high-profile former deputy attorney general who oversaw special counsel Robert Mueller’s Russia investigation, is joining a corporate law firm that is home to several other senior Republican law-enforcement officials.

Mr. Rosenstein’s role as a partner at King & Spalding LLP is his first job in the private sector after nearly 30 years at the Justice Department, which included a tumultuous stint as its No. 2 official managing Mr. Mueller’s probe into President Trump and his associates.

In his new capacity, Mr. Rosenstein, 54, will still be able to keep an eye on the White House—as his office directly overlooks it—but he says the job’s location had no bearing on his decision to join the Atlanta-based firm. He will represent companies and other clients in regulatory, congressional and other investigations as part of the firm’s special matters and government investigations team, once headed by Federal Bureau of Investigation Director Christopher Wray.

Another former deputy attorney general, Sally Yates, who served under President Obama and briefly for the Trump administration as acting attorney general, is also a partner on the team, as is Mr. Wray’s former chief of staff, Zack Harmon.

“It really fit what I wanted to do in private practice,” Mr. Rosenstein, who left the department in May, said in an interview. “This was an ideal opportunity for me to put my experience to use counseling clients.”