Tiffani Thiessen turned 50-years-old on Tuesday.

And to celebrate the Saved By The Bell star - who was 15 when she first started playing Kelly Kapowski in the classic sitcom - posed nude in her bed.

The brunette beauty looked tanned and toned as she held up a sheet to her chest to protect her modesty with her dark locks flowing down one side in a photograph by Rebecca Sanabria.

'Over the hill,' the TV star wrote in her caption even though she looked anything but over the hill. 

The looker added the hashtag for 'This is 50.' 

The comments were pretty intriguing. Sarah Michelle Gellar said, 'Looks pretty [three fire emojis] to me,' while Valerie Bertinelli called her 'a hot mama' and her former SBTB costar Mario Lopez said, 'Welcome to the 5th level kid!'

Mario turned 50-years-old in October. 

A post shared by Tiffani Thiessen (@tiffanithiessen)

Tiffani Thiessen turned 50-years-old on Tuesday. And to celebrate the Saved By The Bell star - who was 15 when she first started playing Kelly Kapowski in the classic sitcom - posed nude in her bed. Sarah Michelle Gellar said, 'Looks pretty [three fire emojis] to me.' Her former SBTB costar Mario Lopez said, 'Welcome to the 5th level kid!' Mario turned 50-years-old in October. Jennifer Love Hewitt also chimed in

Valerie Bertinelli called her 'a hot mama' and added a fire emoji

Jenna Fischer added, 'Well done. Starting the 50s exactly right. Happy birthday!'

Jennifer Love Hewitt also chimed in: 'Happy Birthday! I remember knowing you as a teenager and hoping to be as gorgeous as you one day! And I still feel the same! You make 50 look great! ❤️'

Jenna Fischer added, 'Well done. Starting the 50s exactly right. Happy birthday!' 

Vanessa Lachey and Brittany Cartwright hit the like button. 

Tiffani celebrated her big day by getting a massage at Happy Feet in Encino. The star went bare-faced for the outing, sporting a large grey California sweatshirt and black sweatpants.

She was joined by husband Brady Smith, 52, for the pampering session, and was later seen running a package at the UPS Store and grabbing a bite at Uncle Bernie's Deli.

Last year Tiffani admitted even over the last decade she has changed her outlook and learned not to care what people think.

Noting her 'confidence wasn't 100 percent' when she turned 40.

She added: 'When I was turning 40, I feel like I had more personal pressure on myself to look the best I could.

'I feel so much more at ease now than I did even ten years ago. I don't know if it's me just not giving a s***.'

The mum of two - who has son Holt Fisher, three, and 13-year-old daughter Harper - noted that her 'body was changing so much hormonally and mentally' when she was having her children.

The star celebrated her big day by getting a massage at Happy Feet in Encino

The actress went bare-faced for the outing, sporting a large grey California sweatshirt and black sweatpants

She was joined by husband Brady Smith, 52, for the pampering session, and was later seen running a package at the UPS Store and grabbing a bite at Uncle Bernie's Deli

Her big hit was Saved By The Bell. (l-r) Berkley as Jessie Spano, Mario Lopez as A.C. Slater, Thiessen as Kelly Kapowski, Dustin Diamond as Screech Powers, Mark-Paul Gosselaar as Zack Morris, Lark Voorhies as Lisa Turtle

Last year she said: 'I can only age the way I'm going to age, right? I'm the best I can be and I'm taking care of myself and doing things that I know will benefit the outside exterior of myself that people are seeing.' Seen left with Elizabeth Berkley right

Tiffani admitted even over the last decade she has changed her outlook and learned not to care what people think. Noting her 'confidence wasn't 100 percent' when she turned 40. She added: 'When I was turning 40, I feel like I had more personal pressure on myself to look the best I could' seen on SBTB

Now, she's 'at a good place' and focused on 'raising happy, healthy kids that are going to do well for themselves and society'.

When it comes to staying healthy herself, she explained: 'I'm doing it for myself, I'm doing it for my kids, my husband.

Thiessen has been married to Brady Smith since 2005. 

'I want to be around for as long as possible of course, to be able to see my kids grow up and have kids of their own, and all those things that are much more important to me now.' 

She also said she felt an 'added pressure of what people were saying' when she starred on SBTB.

Appearing on the Good Instincts podcast from Dear Media, Tiffani told host and dietitian Shira Barlow: 'I think people will say things, you know, and maybe expect me to look a certain way, yes.

'But I mean, it's just not realistic. I can only age the way I'm going to age, right? 

'I'm the best I can be and I'm taking care of myself and doing things that I know will benefit the outside exterior of myself that people are seeing.'

Thiessen has become more comfortable with people talking about her appearance

Appearing on the Good Instincts podcast last year, Tiffani, told host and dietitian Shira Barlow: 'I think people will say things, you know, and maybe expect me to look a certain way, yes. But I mean, it's just not realistic'

'But yeah, those people don't know what's happening on the inside, right? Because that's what actually helps the outside.'

In 2020 she shared a swimsuit photo when she was conducting 'research' as she embarked on a 'character study' ahead of her Saved By The Bell reboot.

The star dug up an old swimsuit picture of herself from the original run of the sitcom, which ran from 1989 to 1993.

Tiffani captioned the picture: '#tbt #research #characterstudy,' adding a heart emoji.

During the show her character worked as a lifeguard and the swimsuit look Tiffani posted to Instagram was the uniform for that job.

The reboot lasted only two seasons.

She dished to Hollywood Life that she thinks the key to staying in shape is to not 'panic' if you gain a little weight.

'What is panic going to do?' she asked. 'They say stress actually adds pounds, so if I stress it’s going to be worse, right?'

Mama: Thiessen and family attend Disney+ Original Movie Zombies 3 Los Angeles Premiere at  in Santa Monica in 2022

Sleek: Thiessen attends The 12th Annual Television Academy Honors at the Beverly Wilshire Four Seasons Hotel in 2019

She added that she 'always tries to live her life in balance,' which includes the way she eats. She shared: 'I’ve never been one to go extreme either way [with dieting].

'I’ve never been one to eat bad all the time and I’ve never been one to always be healthy. I’m like an 80-20 per cent kind of person.

'I try to be because I love food. I love to cook… Eating a salad three times a day is not always what I want to do. So, I think it’s all about balance.'

Thiessen was born in Long Beach, California and participated in beauty pageants at a young age. She was crowned Miss Junior America in 1987. 

She then modeled for Teen magazine for years before being cast on Saved By The Bell. She was on the series from 1989 until 1993.

At the same time she guest-starred on series such as Married... with Children, Charles in Charge and Step by Step.

In 1992, she starred in the TV movie Saved by the Bell: Hawaiian Style.

She then continued with starring in spin-off Saved by the Bell: The College Years in its single season (1993–94) and in television movie Saved by the Bell: Wedding in Las Vegas (1994).

Next came Beverly Hills, 90210; she stepped in after Shannen Doherty exited the high school drama.

Then came more TV movies: The Stranger Beside Me (1995) and She Fought Alone (1995), Sweet Dreams and Buried Secrets in 1996 and the films Speedway Junky (1999), From Dusk Till Dawn 2: Texas Blood Money (1999), Love Stinks (1999) and The Ladies Man (2000).

In 2015, Thiessen reunited with Saved By the Bell costars Mark-Paul Gosselaar, Elizabeth Berkley, Dennis Haskins and Mario Lopez on The Tonight Show Starring Jimmy Fallon, in which they appeared in a Saved by the Bell sketch.

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