The Hawks have an unusual history in free agency. Over the course of their more-than-50-year history since moving to Atlanta, there aren't exactly a plethora of great free agent signings jumping off the page, but they have found the proverbial needle in the haystack on a couple of occasions. The top three or four signings they've ever made in free agency have had a significant impact on the franchise, and are etched into the annals of Hawks' history as some of the best to ever pull on the jersey. There's a fairly hefty gap in quality thereafter, but regardless, let's take a look at the seven best free agent signings in Hawks' franchise history.

7. Lou Williams (2012)

After seven fruitful seasons with the Sixers, Lou Williams signed with the Hawks in the summer of 2012 after finishing runner-up in the Sixth Man of the Year Award the season prior, and his presence immediately added plenty of scoring punch off the bench. Unfortunately, 39 games into his first season with the team and boasting averages of 14.1 points and 3.6 assists, he tore his ACL in January 2013, an injury which caused him to miss the rest of that season and the beginning of the next. He returned to play 60 games the next season as the Hawks made the playoffs for the seventh straight year, but he unsurprisingly took a little while to get going and averaged just over ten points in 2013-14. He was subsequently traded to Toronto. Admittedly it's not a great start to this list, but I did warn you it lacks depth!

6. Demarre Carroll (2013)

Demarre Carroll signed with the Hawks after bouncing around the league for a few years, and though he only played two seasons in Atlanta it was probably the most successful leg of his ten-year career. Carroll was a solid enough outside threat during his time with the Hawks, hitting 36.2% of three-point attempts in his first season with them and 39.5% in his second. More important than that, however, was the defensive intensity he brought on a nightly basis, which helped him to earn the big contract he signed with Toronto after two seasons in Atlanta. Carroll was a major part of the 60-win Atlanta team of 2014-15, a team which finished first in the Eastern Conference and made its way through to the Conference Finals before being swept by LeBron James and the Cavs.

5. Moses Malone (1988)

From a pure talent perspective, Moses Malone would be right at the top of this list, but by the time he signed with the Hawks he was 33 years of age and had already played out the majority of his Hall of Fame career. But while he wasn't in his absolute prime with Atlanta, Malone still had three productive seasons there, playing over 80 games in each of them and putting up some impressive numbers. He averaged 19.6 points and 10.9 rebounds over his first two seasons, leading them to a 52-win season in the first of those and also making his 12th consecutive All-Star appearance that same season. Aged 35 at the beginning of his third season with the franchise, an inevitable decline ensued and he averaged just 10.6 points and 8.1 rebounds, but he still played a key role in returning them to the playoffs for the second time in his three years there. He headed to Milwaukee after that season, concluding a stint with the Hawks which while not as successful as the team had hoped when they signed him, still yielded a couple of good years.

4. Paul Millsap (2013)

Millsap played the first seven years of his NBA career in Utah and was a reliable member of their team, but upon signing with the Hawks in free agency in 2013 he took his game to a new level. Millsap was the quintessential Swiss Army knife on a Hawks team which made the playoffs in each of his four seasons with the team, the second of which was their famous 60-win season which culminated in a Conference Finals appearance. He was an All-Star every season in Atlanta, averaging at least 16.7 points, 7.7 rebounds and 3.1 assists across those four years. In a 15-year career, Millsap's best four years were those he spent in Atlanta, a tenure during which he established himself as one of the best free agent signings the team has ever made.

3. Dikembe Mutombo (1996)

Now we're getting to the really good stuff. Dikembe Mutombo spent nearly five years of his storied NBA career with the Hawks, signing with the team in free agency after five impressive years in Denver to kick off his NBA career. Those first five years yielded double-double averages every year, three All-Star appearances and a Defensive Player of the Year Award, and he added significantly to his already extensive trophy cabinet while in Atlanta. He averaged in excess of 11 rebounds every year with the team, but most important, of course, was his defensive presence, a presence which yielded at least 2.8 blocks a game each season in Atlanta and saw him named Defensive Player of the Year three out of his five seasons there, and voted to the All-Defensive First or Second Team every year. Unfortunately the team didn't have all that much success while he was there – though they won 50 or more games in each of his first two seasons with the franchise, they were unable to make it past the second round of the playoffs and subsequently fell out of the postseason. But despite that, Mutombo remains one of the best players to pull on a Hawks jersey.

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2. Dan Roundfield (1978)

After spending three seasons in Indiana, Dan Roundfield signed with the Hawks in 1978 apparently so that his father would be able to see more of his games – a decision which proved to be pretty beneficial for Atlanta. Like Mutombo, Roundfield was a defensive force, making the All-Defensive First or Second Team in five successive seasons between 1980 and 1984. He virtually averaged a double-double in every year with the team – he grabbed 9.9 rebounds per game in the final of his six years with the team – while also putting in close to 20 points and three assists during a stint in which the franchise made the playoffs in five out of six seasons. Also like Mutombo, Roundfield's tenure with the team unfortunately didn't go much further than that, with only one of those playoff runs extending past the first round, but nonetheless his illustrious career with the team made him a fantastic free agency pick-up.

1. Joe Johnson (2005)

The best free agent signing the Hawks have ever made, Joe Johnson spent seven elite seasons with the team after signing with them as a 24-year-old. In his first season with in Atlanta he averaged 20.2 points, 4.1 rebounds and 6.5 assists, and that was arguably his worst year with them – it was the only of his seven seasons as a Hawk in which he wasn't voted to the All-Star team. Johnson was handsomely paid for his efforts and has subsequently been oft-maligned by the Hawks supporter base, but there's no doubting that he was one of the better players the team has ever had. After missing the playoffs in his first two seasons there, they would make it in each of his next five, making it past the first round on five of those occasions. In 2012, seven seasons and a hell of a lot of money after he initially moved to Atlanta from the Phoenix Suns, Johnson was shipped off to Brooklyn as a 31-year-old, but while he had a couple of productive years there his decline as a player had begun. It was in Atlanta where Johnson spent the best stretch of his career, solidifying his spot as the Hawks' best ever free agent signing.