Actress-singer Jennifer Lopez used Instagram to show off her fit figure after celebrating her 51st birthday.

Lopez rang in her 51st birthday with her loved ones. She flaunted her figure as she took to Instagram with a mirror selfie in black activewear, after celebrating her birthday on Friday, reports dailymail.co.uk.

"Just finished a great post-birthday celebration workout and helped to support hunger awareness," she wrote along with the picture.

She was also praised by fiance Alex Rodriguez, 44, who took to his Instagram Story with a photograph, writing: "My queen".

Rodriguez also shared a video tribute for his lady love, which had plenty of romantic couple moments.

He captioned the video: "Happy Birthday, Macha!!! Every moment with you is magical. You are the greatest partner, the best mom, the most amazing performer. A role model. A hero. An inspiration. I'm so proud of you. I love you so much!"

Lopez responded: "Omg!! I love you and feel so blessed today to have you to celebrate with my baby!!"

Lopez also shared a picture of herself sitting on the beach with Rodriguez as their children enjoy the beach outing.

She wrote: "Exactly where we need to be."