# List of state roads in Connecticut

In the U.S. state of Connecticut, state highways are grouped into signed routes, unsigned special service roads (SSR), and unsigned state roads (SR). State roads are feeder roads that provide additional interconnections between signed routes, or long entrance/exit ramps to expressways. Roads classified by the Connecticut Department of Transportation as state roads are given an unsigned number designation between 500 and 999, with the first digit depending on which Maintenance District the road is primarily located in. Below is a list of the state roads that are classified as arterial roads.
| Number | Length (mi) | Length (km) | Southern or western terminus | Northern or eastern terminus | Local names | Formed | Removed | Notes |
| SR 500 | 0.51 | 0.82 | I-84 / US 6 / Route 2 in East Hartford | Governor Street in East Hartford | — | — | — | |
| SR 501 | 0.77 | 1.24 | I-84 / US 6 in West Hartford | Park Road in West Hartford | Trout Brook Connector | — | — | |
| SR 502 | 6.31 | 10.15 | Route 2 in East Hartford | US 6 / US 44 in Manchester | East River Drive Extension, Silver Lane, Spencer Street | — | — | |
| SR 503 | 0.68 | 1.09 | Sisson Avenue in Hartford | I-84 / US 6 in Hartford | Sisson Avenue Connector | — | — | |
| SR 504 | 0.70 | 1.13 | Flatbush Avenue in Hartford | I-84 / US 6 in Hartford | — | — | — | |
| SR 505 | 0.53 | 0.85 | Route 175 in Newington | Route 9 in Newington | Fenn Road | — | — | |
| SR 508 | 1.82 | 2.93 | Route 4 in Farmington | I-84 / US 6 in Farmington | — | — | — | |
| SR 509 | 0.51 | 0.82 | Route 322 in Southington | Route 10 in Southington | Clark Street | — | — | |
| SR 510 | 2.55 | 4.10 | US 5 in East Windsor | US 5 in Enfield | Main Street, Depot Hill Road | — | — | |
| SR 511 | 0.38 | 0.61 | Route 10 in Plainville | Route 72 in Plainville | Hooker Street | — | — | |
| SR 513 | 0.67 | 1.08 | Route 75 in Suffield | End state maintenance | Bridge Street | — | — | |
| SR 514 | 0.20 | 0.32 | US 5 in Enfield | Route 190 / Pearl Street in Enfield | Franklin Street | — | — | |
| SR 515 | 0.20 | 0.32 | Pearl Street in Enfield | US 5 / Route 190 in Enfield | Frew Terrace | — | — | |
| SR 516 | 0.18 | 0.29 | Route 2 in East Hartford | Main Street (SR 517) in East Hartford | Willow Street Extended | — | — | |
| SR 517 | 1.24 | 2.00 | Route 2 in East Hartford | US 5 / Route 15 in East Hartford | Main Street, High Street | — | — | |
| SR 518 | 0.45 | 0.72 | Silver Lane (SR 502) in East Hartford | I-84 / US 6 in East Hartford | Roberts Street | — | — | |
| SR 524 | 0.31 | 0.50 | Route 3 in Cromwell | Route 372 in Cromwell | Berlin Road | — | — | |
| SR 526 | 1.66 | 2.67 | Route 187 in Suffield | Route 168 in Suffield | Sheldon Street | — | — | |
| SR 527 | 2.05 | 3.30 | Route 30 in Vernon | Route 74 / Route 83 in Vernon | West Street | — | — | |
| SR 528 | 2.59 | 4.17 | Route 190 in Somers | Route 83 in Somers | Turnpike Road | — | — | |
| SR 529 | 1.33 | 2.14 | Route 173 in West Hartford | Newington Avenue in Hartford | New Britain Avenue | — | — | |
| SR 530 | 0.58 | 0.93 | Wethersfield Avenue in Hartford | Brainard Road in Hartford | Airport Road | — | — | |
| SR 531 | 1.39 | 2.24 | Route 4 in Farmington | I-84 / US 6 in Farmington | South Road, Colt Highway | — | — | |
| SR 532 | 0.44 | 0.71 | Route 177 in Plainville | Route 10 in Southington | Washington Street, Birch Street | — | — | |
| SR 533 | 4.03 | 6.49 | US 6 / US 44 / Route 85 in Bolton | Route 30 in Vernon | Cider Mill Road, Tunnel Road | — | — | |
| SR 534 | 4.45 | 7.16 | Route 83 in Manchester | Route 85 in Bolton | Charter Oak Street, Highland Street | — | — | |
| SR 535 | 0.21 | 0.34 | Route 71 in West Hartford | I-84 / US 6 in West Hartford | Ridgewood Road | — | — | |
| SR 536 | 1.53 | 2.46 | Route 372 in Plainville | Route 372 in Plainville | Pine Street, Woodford Avenue, Crooked Street | — | — | |
| SR 539 | 3.70 | 5.95 | Route 20 in Hartland | Route 189 in Granby | Mountain Road | — | — | |
| SR 540 | 1.43 | 2.30 | Route 189 in East Granby | Route 187 in East Granby | Hatchett Hill Road | — | — | |
| SR 541 | 0.82 | 1.32 | Tunnel Road (SR 533) in Vernon | Route 30 in Vernon | South Frontage Road, Bolton Road | — | — | |
| SR 542 | 0.30 | 0.48 | Tunnel Road (SR 533) in Vernon | Bolton Road (SR 541) in Vernon | Ferguson Road | — | — | |
| SR 543 | 0.38 | 0.61 | Route 314 in Wethersfield | Maple Avenue at Wethersfield–Hartford town line | Berlin Turnpike | — | — | |
| SR 545 | 0.15 | 0.24 | Route 66 in Middletown | Route 9 / Route 17 in Middletown | Washington Street | — | — | |
| SR 549 | 1.14 | 1.83 | US 6 in Farmington | South Road (SR 531) in Farmington | Birdseye Road | — | — | |
| SR 552 | 0.23 | 0.37 | US 6 in Farmington | Route 10 in Farmington | Scott Swamp Road | — | — | |
| SR 555 | 1.30 | 2.09 | Route 372 in New Britain | Main Street in New Britain | West Main Street | — | — | |
| SR 565 | 1.73 | 2.78 | Route 179 in Canton | US 44 in Canton | Maple Avenue | — | — | |
| SR 569 | 0.17 | 0.27 | I-91 in Windsor Locks | Route 159 in Windsor Locks | Lawnacre Road | — | — | |
| SR 571 | 1.52 | 2.45 | Route 71A / Route 372 in Berlin | Route 9 in Berlin | — | — | — | |
| SR 572 | 0.48 | 0.77 | Route 9 in Berlin | US 5 / Route 15 in Berlin | Frontage Road, Worthington Ridge Road | — | — | |
| SR 585 | 1.25 | 2.01 | Route 168 in Suffield | Point Grove Road at the Massachusetts state line in Suffield | Babbs Road | — | — | |
| SR 597 | 0.58 | 0.93 | Route 10 in Southington | I-84 in Southington | — | — | — | |
| SR 598 | 0.76 | 1.22 | Pulaski Circle in Hartford | I-91 in Hartford | Whitehead Highway | — | — | |
| SR 600 | 0.67 | 1.08 | Route 138 in Lisbon | Route 169 in Lisbon | Kinsman Hill Road | — | — | |
| SR 602 | 3.28 | 5.28 | Route 154 in Essex | Route 80 in Deep River | Main Street, Warsaw Street | — | — | |
| SR 603 | 3.54 | 5.70 | Route 85 in Hebron | Route 316 in Andover | London Road, Boston Hill Road | — | — | |
| SR 604 | 0.80 | 1.29 | Route 153 in Essex | Main Street (SR 602) in Essex | Westbrook Road | — | — | |
| SR 605 | 0.30 | 0.48 | Route 165 in Preston | Route 164 in Preston | Old Shetucket Turnpike | — | — | |
| SR 607 | 2.54 | 4.09 | Route 12 in Killingly | US 6 in Killingly | Westcott Road | — | — | |
| SR 608 | 4.32 | 6.95 | Norwich Avenue (SR 616) / McGrath Lane in Lebanon | Fitchville Road at Bozrah–Norwich town line | Norwich Avenue, Fitchville Road | — | — | |
| SR 609 | 0.97 | 1.56 | Route 151 in East Haddam | Route 149 in East Haddam | Leesville Road | — | — | |
| SR 610 | 2.16 | 3.48 | Route 32 in Franklin | Route 207 in Franklin | Baltic Road | — | — | |
| SR 612 | 0.14 | 0.23 | Route 163 in Bozrah | Fitchville Road (SR 608) in Bozrah | Haughton Road | — | — | |
| SR 614 | 2.63 | 4.23 | US 1 in Groton | Route 184 in Groton | Allyn Street, Mystic Street, Cow Hill Road | — | — | |
| SR 615 | 1.32 | 2.12 | Route 2 in Colchester | Route 85 in Colchester | Old Hartford Road, Broadway | — | — | |
| SR 616 | 6.83 | 10.99 | Route 85 in Colchester | Road end in Lebanon | Norwich Avenue, McGrath Lane | — | — | |
| SR 617 | 0.85 | 1.37 | I-95 / Route 2 in North Stonington | Route 49 in North Stonington | — | — | — | |
| SR 618 | 0.69 | 1.11 | Westcott Road (SR 607) in Killingly | US 6 in Killingly | North Frontage Road | — | — | |
| SR 619 | 0.49 | 0.79 | I-395 in Killingly | Westcott Road (SR 607) in Killingly | Gauthier Avenue | — | — | |
| SR 620 | 0.31 | 0.50 | Route 171 in Union | End state maintenance | Mashapaug Road | — | — | |
| SR 621 | 0.10 | 0.16 | Route 9 / Route 153 in Essex | Route 154 in Essex | — | — | — | |
| SR 623 | 1.23 | 1.98 | One-way frontage road along southbound I-95 in New London and Waterford | One-way frontage road along southbound I-95 in New London and Waterford | North Frontage Road, Parkway North | — | — | |
| SR 624 | 0.60 | 0.97 | I-95 in Waterford | US 1 in New London | Parkway South, South Frontage Road | — | — | |
| SR 625 | 0.99 | 1.59 | US 1 in Westbrook | Route 145 in Westbrook | Grove Beach Road | — | — | |
| SR 626 | 0.25 | 0.40 | Route 216 / Route 184 in North Stonington | Rhode Island state line | Providence New London Turnpike | — | — | |
| SR 627 | 0.91 | 1.46 | Route 201 in North Stonington | Route 2 in North Stonington | Mystic Road | — | — | |
| SR 628 | 0.33 | 0.53 | US 1 in Old Saybrook | End state maintenance | Spring Brook Road | — | — | |
| SR 629 | 0.26 | 0.42 | Route 138 in Griswold | I-395 / Route 164 in Griswold | — | — | — | |
| SR 630 | 0.36 | 0.58 | Route 164 in Griswold | Route 138 / I-395 in Griswold | — | — | — | |
| SR 632 | 0.80 | 1.29 | Route 195 in Mansfield | US 6 / Mansfield City Road in Mansfield | North Frontage Road | — | — | |
| SR 633 | 0.79 | 1.27 | Mansfield City Road in Mansfield | US 6 / Route 195 in Mansfield | South Frontage Road | — | — | |
| SR 635 | 0.58 | 0.93 | Huntington Street (SR 641) in New London | Briggs Street (SR 638) in New London | Williams Street | — | — | |
| SR 636 | 0.64 | 1.03 | Norwood Avenue in New London | Route 32 in New London | Briggs Street, Briggs-Mohegan Connector, Mohegan Avenue | — | — | |
| SR 637 | 0.51 | 0.82 | Route 11 in Colchester | Route 354 in Colchester | Lake Hayward Road | — | — | |
| SR 638 | 0.16 | 0.26 | Williams Street (SR 635) in New London | Briggs Street (SR 638) / Briggs-Mohegan Connector (SR 638) in New London | Briggs Street | — | — | |
| SR 639 | 0.77 | 1.24 | US 1 / Jefferson Avenue in New London | US 1 in New London | Colman Street | — | — | Signed as southbound US 1 |
| SR 640 | 0.14 | 0.23 | Route 74 in Willington | Route 32 in Willington | Phelps Way | — | — | |
| SR 641 | 1.76 | 2.83 | US 1 in New London | US 1 in New London | South Frontage Road, Huntington Street, Jay Street, Truman Street, Bank Street | — | — | |
| SR 642 | 2.65 | 4.26 | Route 2 / Route 32 in Norwich | Route 2 / Route 32 / Route 169 in Norwich | Town Street, Washington Street | — | — | |
| SR 643 | 0.13 | 0.21 | US 1 in New London | Route 213 in New London | Lee Avenue | — | — | |
| SR 644 | 0.75 | 1.21 | Route 97 in Pomfret | US 44 / Route 169 in Pomfret | Murdock Road | — | — | |
| SR 646 | 0.18 | 0.29 | Route 82 in Norwich | Route 82 in Norwich | North Thames Street | — | — | |
| SR 647 | 0.24 | 0.39 | I-395 in Plainfield | Route 12 in Plainfield | Lathrop Road | — | — | |
| SR 649 | 2.69 | 4.33 | Route 349 in Groton | US 1 in Groton | Rainville Avenue, Poquonnock Road, High Rock Road, Tower Avenue, South Road | — | — | |
| SR 654 | 0.28 | 0.45 | Route 27 in Stonington | I-95 in Stonington | — | — | — | |
| SR 660 | 1.64 | 2.64 | Route 97 in Norwich | Route 138 in Sprague | Bridge Street | — | — | |
| SR 661 | 0.11 | 0.18 | Route 32 in Windham | Route 66 in Windham | Thread City Crossing (Frog Bridge) | — | — | |
| SR 664 | 5.70 | 9.17 | Route 14 in Plainfield | US 6 in Killingly | Lake Street, Snake Meadow Road | — | — | |
| SR 668 | 2.00 | 3.22 | Route 169 in Canterbury | Route 12 in Canterbury | Butts Bridge Road | — | — | |
| SR 680 | 0.99 | 1.59 | Route 2 in Ledyard | Route 2 / Wintechog Hill Road in North Stonington | MGM Drive, Foxwoods Boulevard | — | — | |
| SR 693 | 1.41 | 2.27 | Route 32 in Waterford | I-395 in Montville | Montville Connector | — | — | |
| SR 695 | 4.49 | 7.23 | I-395 in Plainfield | US 6 in Killingly | Connecticut Turnpike | — | — | |
| SR 700 | 1.73 | 2.78 | Route 130 / Water Street in Bridgeport | Route 130 / State Street Extended in Bridgeport | Fairfield Avenue | — | — | Westbound couplet of Route 130 |
| SR 702 | 0.81 | 1.30 | US 5 in Wallingford | I-91 in Wallingford | Wharton Brook Connector | — | — | |
| SR 703 | 0.20 | 0.32 | Route 63 in Bethany | Route 42 in Bethany | Litchfield Turnpike | — | — | |
| SR 705 | 2.63 | 4.23 | Route 162 in West Haven | Route 162 in West Haven | Ocean Avenue, Platt Avenue | — | — | |
| SR 706 | 0.82 | 1.32 | Howe Street in New Haven | Route 10 in New Haven | North Frontage Road | — | — | Westbound couplet of Route 34 |
| SR 707 | 3.62 | 5.83 | Whitney Avenue at New Haven–Hamden town line | Route 10 / Dixwell Avenue (SR 717) in Hamden | Whitney Avenue | — | — | |
| SR 708 | 0.32 | 0.51 | Old Gate Lane in Milford | I-95 / Woodmont Road in Milford | Old Gate Lane | — | — | |
| SR 709 | 0.27 | 0.43 | Route 63 in Naugatuck | Route 8 in Naugatuck | South Main Street | — | — | |
| SR 710 | 0.31 | 0.50 | Route 8 / Union Street (SR 723) in Naugatuck | Route 8 in Naugatuck | North Main Street | — | — | |
| SR 711 | 0.81 | 1.30 | Penny Avenue (SR 730 and SR 743) in Trumbull | Route 108 in Trumbull | Huntington Turnpike | — | — | |
| SR 712 | 0.24 | 0.39 | Route 110 in Shelton | Route 34 in Derby | Bridge Street | — | — | |
| SR 713 | 0.27 | 0.43 | Route 15 in Fairfield | Route 59 in Fairfield | Congress Street | — | — | |
| SR 714 | 0.24 | 0.39 | Huntington Street in Shelton | Route 108 in Shelton | Bridgeport Avenue, Center Street | — | — | |
| SR 715 | 0.51 | 0.82 | I-91 in North Haven | Route 103 in North Haven | Universal Drive, Montowese Avenue | — | — | |
| SR 717 | 1.15 | 1.85 | Route 10 / Whitney Avenue (SR 707) in Hamden | US 5 in North Haven | Dixwell Avenue | — | — | |
| SR 718 | 0.27 | 0.43 | US 1 in Guilford | I-95 in Guilford | Goose Lane | — | — | |
| SR 719 | 2.02 | 3.25 | Route 123 in Norwalk | US 7 in Norwalk | Main Avenue | — | — | |
| SR 720 | 0.26 | 0.42 | Hartford Turnpike in North Haven | US 5 in North Haven | Devine Street | — | — | |
| SR 721 | 1.85 | 2.98 | Route 67 in Seymour | Old Turnpike in Beacon Falls | North Street, North Main Street, South Main Street | — | — | |
| SR 722 | 0.37 | 0.60 | US 1 in Bridgeport | Route 8 in Bridgeport | Chopsey Hill Road | — | — | |
| SR 723 | 0.16 | 0.26 | North Main Street (SR 710) in Naugatuck | North Main Street (SR 710) in Naugatuck | Union Street, Golden Court | — | — | |
| SR 724 | 0.6 | 0.97 | MLK Blvd./S Frontage Rd. in New Haven | Interstate 91 and Interstate 95 in New Haven | Oak Street Connector | — | — | Originally part of Route 34 until the early-2020s. |
| SR 725 | 0.08 | 0.13 | Route 22 in North Haven | Route 15 in North Haven | Hartford Turnpike | — | — | |
| SR 816 | 1.7 | 2.7 | Route 34 in Newtown | River Rd No. 1 in Southbury | | — | — | Original Route 6 surface routing, before I84. |