Kobe Bryant would've turned 44 on Tuesday ... and his wife, Vanessa, penned a heartfelt birthday note on Instagram, writing she loves and misses him so much.
Vanessa posted a photo of her and her NBA legend hubby from 2009 ... when Kobe won his 4th NBA title and 1st NBA Finals MVP.
You can see Bryant -- wearing his 2009 NBA championship shirt and hat -- hugging Vanessa post-game ... and they were both all smiles.
"Happy birthday, baby!" the 40-year-old said Tuesday.
"I love you and miss you so much! #44 ❤️ @kobebryant"
Since Kobe -- who she married in April 2001 -- and daughter Gigi's untimely death, Vanessa has been honoring them in countless ways ... including getting tattoos in their honor, launching the Mambacita clothing line, and taking her 3 other daughters to Italy -- where Kobe was raised.
"Visited Reggio Calabria," Vanessa said in July, "a city my husband lived in when he was about 8 years old."
Of course, Bryant went on to play 20 seasons in the NBA -- winning 5 championships and 2 NBA Finals MVP ... was an 18-time NBA All-Star, broke numerous records, and is known as one of the best NBA players ever.
Happy Bday, Kobe!