A "quiet achiever" is a person who succeeds or accomplishes things without drawing attention to themselves. They may not seek recognition or praise but still make significant achievements. Full definition
Having cut his teeth on TV's «That 70's Show», Grace featured in Traffic and Mona Lisa Smile, before his biggest year yet in 2004 saw him co-star with much more seasoned performers in quiet achievers In Good Company and P.S. (as well as the wretched teen - flop Win a Date with Tad Hamilton!). (hoopla.nu)
It's a pity, cos The Night Listener is a fantastic quiet achiever. (hoopla.nu)
It has the right mix of light science fiction and over the top sentimentality to cover a multitude of audiences, and quiet achiever Bill Nighy pulls it altogether. (trespassmag.com)