This is a question that I thought about recently, and I thought would be interesting to the MO community.
What are some famous conjectures, more specifically those that attracted a lot of attention and had a non-trivial impact on the direction of at least one mathematical subject area for some time, that were named after particular mathematicians which were resolved within their lifetimes?
Two prominent examples in number theory include the following:
1) The Taniyama-Shimura conjecture, asserting that every elliptic curve over $\mathbb{Q}$ is modular. This conjecture was shown to imply Fermat's Last Theorem in the 1980s, and whose semi-stable case was famously resolved by Taylor and Wiles in 1995. Breuill, Conrad, Diamond, and Taylor then finished the remaining cases in 2000. While Taniyama tragically died not long after making the conjecture, Goro Shimura only passed away recently and certainly saw the resolution of this conjecture.
2) The Weil-conjectures, which can be viewed as a form of Riemann hypothesis for algebraic varieties over finite fields, was famously resolved by Deligne in the 1970s. Weil, who lived until 1998, certainly saw the resolution of these conjectures.
A non-example, off by about a decade, is Mordell's conjecture, which is the assertion that any algebraic curve defined over a number field having genus $g \geq 2$ has at most finitely many $K$-rational points for any number field $K$. Mordell died in 1972, 11 years before Faltings proved his conjecture in 1983.